gstplugin.c: define PACKAGE if it hasn't been defined yet
gstplugin.c: define PACKAGE if it hasn't been defined yet

Since it's secretly required by GST_PLUGIN_DEFINE and we don't want
people to trip over this if they're trying to compile their code
without autotools.

brianthelion/gst-recipes,kirankrishnappa/gst-template,Forvater/gst-template,Forvater/gst-template,landswellsong/gst-template,brianthelion/gst-recipes,brianthelion/gst-recipes,theconsummate/gst-plugin,kirankrishnappa/gst-template,Forvater/gst-template,kirankrishnappa/gst-template,theconsummate/gst-plugin,brianthelion/gst-recipes,landswellsong/gst-template