Check for bash when destination is local fails

[spmp]

When the destination is is local the test for bash over sh fails as:

btrfs-sync /somewhere/local /someotherplace/local
Remote user's shell not bash. Shells other than bash are not supported at the moment

Commenting out the line (https://github.com/nachoparker/btrfs-sync/blob/5647f149ecdb52861b7c3498b8324e16d53ee8bc/btrfs-sync#L136):

${DST_CMD[@]} "echo \$0 | grep bash > /dev/null" || { echo "Remote user's shell not bash. Shells other than bash are not supported at the moment"; exit 1; }