Avoid printing incorrect block indexing time due to uninitialized variable.
Fixes:
init.cpp: In function ‘bool AppInitMain(boost::thread_group&, CScheduler&)’:
init.cpp:1499:56: warning: ‘nStart’ may be used uninitialized in this function [-Wmaybe-uninitialized]
LogPrintf(" block index %15dms\n", GetTimeMillis() - nStart);
^
In this fix I've assumed that block indexing time is only relevant to print in case of fLoaded. Let me know if that assumption is incorrect.