spelling (https://trac.osgeo.org/grass/ticket/1596, merge from devbr6)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@50955 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.topmodel/main.c

@@ -100,7 +100,7 @@ int main(int argc, char **argv)
     param.topidx = G_define_standard_option(G_OPT_R_OUTPUT);
     param.topidx->key = "topidx";
     param.topidx->label =
-	_("Name for output opographic index ln(a/tanB) raster map");
+	_("Name for output topographic index ln(a/tanB) raster map");
     param.topidx->description = _("MASK applied");
     param.topidx->required = NO;
     param.topidx->guisection = _("Output");