r.external: Starting with GDAL 2.0, vector drivers can also be returned (fix -f flag)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@60481 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.external/list.c

@@ -24,6 +24,13 @@ void list_formats(void)
 	GDALDriverH hDriver = GDALGetDriver(iDr);
 	const char *pszRWFlag;
 
+#ifdef GDAL_DCAP_RASTER
+            /* Starting with GDAL 2.0, vector drivers can also be returned */
+            /* Only keep raster drivers */
+            if (!GDALGetMetadataItem(hDriver, GDAL_DCAP_RASTER, NULL))
+                continue;
+#endif
+
 	if (GDALGetMetadataItem(hDriver, GDAL_DCAP_CREATE, NULL))
 	    pszRWFlag = "rw+";
 	else if (GDALGetMetadataItem(hDriver, GDAL_DCAP_CREATECOPY, NULL))