iotests: Skip 103 for refcount_bits=1

Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20171123020832.8165-9-mreitz@redhat.com
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

tests/qemu-iotests/103

@@ -40,6 +40,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file nfs
 _supported_os Linux
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'refcount_bits=1[^0-9]'
 
 IMG_SIZE=64K