Plugin amr: fix regex issue

An unescpaed left brace is rejected by recent versions of perl.

plugins/amr/amr

@@ -133,7 +133,7 @@ sub parse
 
     while (<$log>) {
         # \d protects us against HTML injection here, be careful when changing
-	if (m,SCM:{ID:(\d+) +.* +Consumption: +(\d+) +,) {
+	if (m,SCM:\{ID:(\d+) +.* +Consumption: +(\d+) +,) {
 	    $stations{$1} = $2;
             $signals{$1}++;
 	}