tests: fix warnings on thetvdb resolve shows
tests: fix warnings on thetvdb resolve shows

-Wdiscarded-qualifiers and -Wdeclaration-after-statement such as:

-Wdiscarded-qualifiers
 warning: initialization discards ‘const’ qualifier from pointer target type
 { "CSI: Miami", "CSI - Miami", "78310", "tt0313043" },
   ^~~~~~~~~~~~

-Wdeclaration-after-statement such as:
 warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   gint result = g_test_run ();
   ^~~~

https://bugzilla.gnome.org/show_bug.cgi?id=768557

grilofw/grilo-plugins,jasuarez/grilo-plugins,GNOME/grilo-plugins,GNOME/grilo-plugins,jasuarez/grilo-plugins,grilofw/grilo-plugins