Minor edit to r.external grass module

src/plugins/grass/modules/r.external.qgis.qgm

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE qgisgrassmodule SYSTEM "http://mrcc.com/qgisgrassdatamodule.dtd">
 <qgisgrassmodule label="Link GDAL supported raster loaded in QGIS as GRASS raster" module="r.external">
-	<gdal key="source" label="GDAL raster layer"/>
+	<gdal key="source" label="Loaded layer"/>
 	<option key="output"/>
 	<option key="title" advanced="yes"/>
 	<option key="band" advanced="yes"/>