Bad update to bsd.gstreamer.mk

[jon at jackson-spencer.ca]

It looks like there was a small error introduced when gstreamer 0.8.0
was retired.  At line 72 of bsd.gstreamer.mk this line was removed:

yes_GST_PREFIX=         # empty

This causes the dependency line to be incorrect for ports that say

USE_GSTREAMER=yes

In their Makefiles.  In case that isn't clear, here's a patch:

--- bsd.gstreamer.mk-old        Sat Jun  2 12:44:11 2007
+++ bsd.gstreamer.mk    Sat Jun  2 12:36:48 2007
@@ -69,6 +69,7 @@

 yes_DEPENDS=   multimedia/gstreamer-plugins
 yes_NAME=      gstreamer-plugins
+yes_GST_PREFIX=                # empty

 cdio_DEPENDS=  sysutils/gstreamer-plugins-cdio