Mount failure results in mount flag not being cleaned up

[Nikratio]

It seems s3backer sometimes forgets to reset the "mounted" flag:

> /s3backer --blockSize=512K --size=50G nikratio-test-us/s3backer ~/tmp/mnt
s3backer: auto-detecting block size and total file size...
s3backer: auto-detection failed; using configured block size 512k and file size 50g
fusermount: option allow_other only allowed if 'user_allow_other' is set in /etc/fuse.conf

> sudo vim /etc/fuse.conf 

> ./s3backer --blockSize=512K --size=50G nikratio-test-us/s3backer ~/tmp/mnt
s3backer: auto-detecting block size and total file size...
s3backer: auto-detection failed; using configured block size 512k and file size 50g
s3backer: http://nikratio-test.s3-eu-west-2.amazonaws.com/s3backer/ appears to be already mounted (using mount token 0x2118b1a4)
s3backer: reset mount token with `--reset-mounted-flag', or use `--force' to override

[archiecobbs]

Should be fixed by 1fcfb80.