message: testcase to read missing variant type

Commit ac52113 fixed an issue where reading a variant from a
message when the C++ variant did not contain the type of the
dbus variant caused the message to get into an invalid state.

Add a testcase for this condition.

Change-Id: Iea58a4440d72a1d2969d80f782ec1f316cb5ff29
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
1 file changed