Starting with txindex option produces a bug continually printing "y".

```
sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
bitcoind -daemon -txindex=1 -server=1 &
root@btc:~# Bitcoin server starting
: You need to rebuild the database using -reindex to change -txindex.

Do you want to rebuild the block database now?
yes
y
y
y
y
y
```

strUsage += HelpMessageOpt("-dbcache=<n>", strprintf(_("Set database cache size in megabytes (%d to %d, default: %d)"), nMinDbCache, nMaxDbCache, nDefaultDbCache));
    if (showDebug)
        strUsage += HelpMessageOpt("-feefilter", strprintf("Tell other nodes to filter invs to us by our mempool min fee (default: %u)", DEFAULT_FEEFILTER));
    strUsage += HelpMessageOpt("-loadblock=<file>", _("Imports blocks from external blk000??.dat file on startup"));
    strUsage += HelpMessageOpt("-maxorphantx=<n>", strprintf(_("Keep at most <n> unconnectable transactions in memory (default: %u)"), DEFAULT_MAX_ORPHAN_TRANSACTIONS));
    strUsage += HelpMessageOpt("-maxmempool=<n>", strprintf(_("Keep the transaction memory pool below <n> megabytes (default: %u)"), DEFAULT_MAX_MEMPOOL_SIZE));
    strUsage += HelpMessageOpt("-mempoolexpiry=<n>", strprintf(_("Do not keep transactions in the mempool longer than <n> hours (default: %u)"), DEFAULT_MEMPOOL_EXPIRY));
    strUsage += HelpMessageOpt("-par=<n>", strprintf(_("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)"),
        -GetNumCores(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS));
#ifndef WIN32
    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), BITCOIN_PID_FILENAME));
#endif
    strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by pruning (deleting) old blocks. This mode is incompatible with -txindex and -rescan. "
            "Warning: Reverting this setting requires re-downloading the entire blockchain. "
            "(default: 0 = disable pruning blocks, >%u = target size in MiB to use for block files)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
    strUsage += HelpMessageOpt("-reindex-chainstate", _("Rebuild chain state from the currently indexed blocks"));
    strUsage += HelpMessageOpt("-reindex", _("Rebuild chain state and block index from the blk*.dat files on disk"));
#ifndef WIN32
    strUsage += HelpMessageOpt("-sysperms", _("Create new files with system default permissions, instead of umask 077 (only effective with disabled wallet functionality)"));
#endif
    strUsage += HelpMessageOpt("-txindex", strprintf(_("Maintain a full transaction index, used by the getrawtransaction rpc call (default: %u)"), DEFAULT_TXINDEX));
    strUsage += HelpMessageGroup(_("Connection options:"));
    strUsage += HelpMessageOpt("-addnode=<ip>", _("Add a node to connect to and attempt to keep the connection open"));
    strUsage += HelpMessageOpt("-banscore=<n>", strprintf(_("Threshold for disconnecting misbehaving peers (default: %u)"), DEFAULT_BANSCORE_THRESHOLD));
    strUsage += HelpMessageOpt("-bantime=<n>", strprintf(_("Number of seconds to keep misbehaving peers from reconnecting (default: %u)"), DEFAULT_MISBEHAVING_BANTIME));
    strUsage += HelpMessageOpt("-bind=<addr>", _("Bind to given address and always listen on it. Use [host]:port notation for IPv6"));
    strUsage += HelpMessageOpt("-connect=<ip>", _("Connect only to the specified node(s)"));
    strUsage += HelpMessageOpt("-discover", _("Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)"));
    strUsage += HelpMessageOpt("-dns", _("Allow DNS lookups for -addnode, -seednode and -connect") + " " + strprintf(_("(default: %u)"), DEFAULT_NAME_LOOKUP));
    strUsage += HelpMessageOpt("-dnsseed", _("Query for peer addresses via DNS lookup, if low on addresses (default: 1 unless -connect)"));