tests/qemu-iotests: Restrict test 130 to the 'file' protocol

Using "-drive ...,backing.file.filename=..." only works with the
file protocol, but not with URIs, so mark this test accordingly.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20240315111108.153201-5-thuth@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/130

@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.qemu
 
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 # We are going to use lazy-refcounts
 _unsupported_imgopts 'compat=0.10'