Fix CLI sourcemap argument

Author: intact

sassc.c

@@ -271,7 +271,7 @@ int main(int argc, char** argv) {
         { "help",               no_argument,       0, 'h' },
         { NULL,                 0,                 NULL, 0}
     };
-    while ((c = getopt_long(argc, argv, "vhsl:mMap:t:I:P:", long_options, &long_index)) != -1) {
+    while ((c = getopt_long(argc, argv, "vhslm:Map:t:I:P:", long_options, &long_index)) != -1) {
         switch (c) {
         case 's':
             from_stdin = 1;