libtracker-miner: Don't disable monitoring during crawling
libtracker-miner: Don't disable monitoring during crawling

This meant that no monitors were getting added even though the log
said the opposite, this was because we added a NULL pointer to the
hash table for each GFile.

outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker