tracker-miner-fs: Postpone sparql update on mount after cancellation
tracker-miner-fs: Postpone sparql update on mount after cancellation

This is a less critical task than cancellation, which might be holding
unmount, so perform it after the rush is gone.

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