cmdutils: indent protocols listing

For readability.
Signed-off-by: Lou Logan <lou@lrcd.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

cmdutils.c

@@ -1535,10 +1535,10 @@ int show_protocols(void *optctx, const char *opt, const char *arg)
     printf("Supported file protocols:\n"
            "Input:\n");
     while ((name = avio_enum_protocols(&opaque, 0)))
-        printf("%s\n", name);
+        printf("  %s\n", name);
     printf("Output:\n");
     while ((name = avio_enum_protocols(&opaque, 1)))
-        printf("%s\n", name);
+        printf("  %s\n", name);
     return 0;
 }