add --config option in the usage string

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@48890 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/init/grass.py

@@ -139,7 +139,7 @@ def gfile(*args):
 help_text = r"""
 %s:
   $CMD_NAME [-h | -help | --help] [-v | --version] [-c | -c geofile | -c EPSG:code]
-	  [-text | -gui]
+	  [-text | -gui] [--config param]
 	  [[[<GISDBASE>/]<LOCATION_NAME>/]<MAPSET>]
 
 %s: