When downloading and running Bitcoin core for the first time, after clicking through the "Are you sure you want to open. it?" screen, there's a possibility that macOS will pass an argument like `-psn_0_SOME_ID` to the application, which results in a shutdown as it's an invalid argument:

![v0 19 0rc1 args shutdown](https://user-images.githubusercontent.com/863730/67034964-b026fc00-f0e6-11e9-8462-70d0fcf613e6.png)

This only happens on the first run, subsequent opens will work fine, but we should filter these out, otherwise it's a poor and confusing first experience.

#if defined(WIN32)
    return 2048;
#else
    struct rlimit limitFD;
    if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
        if (limitFD.rlim_cur < (rlim_t)nMinFD) {
            limitFD.rlim_cur = nMinFD;
            if (limitFD.rlim_cur > limitFD.rlim_max)
                limitFD.rlim_cur = limitFD.rlim_max;
            setrlimit(RLIMIT_NOFILE, &limitFD);
            getrlimit(RLIMIT_NOFILE, &limitFD);
        }
        return limitFD.rlim_cur;
    }
    return nMinFD; 
#endif
}
/**
 * this function tries to make a particular range of a file allocated (corresponding to disk space)
 * it is advisory, and the range specified in the arguments will never contain live data
 */
void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {