So we don't unnecessarily scan directories that have no plugins
(or try to open libs). Matches how we limit the search space for
plugin modules to gst/ ext/ sys/ subdirs.
# includedir is builddir because it is used to find gstconfig.h in places
includedir=@abs_top_builddir@
toolsdir=@abs_top_builddir@/tools
-pluginsdir=@abs_top_builddir@
+pluginsdir=@abs_top_builddir@/plugins
girdir=@abs_top_builddir@/gst
bashhelpersdir=@abs_top_builddir@/data/bash-completion/helpers
helpersdir=@abs_top_builddir@/libs/gst/helpers