Clearer message about missing mapping

src/config.c

@@ -347,10 +347,8 @@ void config_parse(int argc, char* argv[], PCONFIGURATION config) {
       config->stream.bitrate = 5000;
   }
 
-  if (inputAdded) {
-    if (config->mapping == NULL) {
-        fprintf(stderr, "Please specify mapping file as default mapping could not be found.\n");
-        exit(-1);
-    }
+  if (config->mapping == NULL) {
+    fprintf(stderr, "Please specify mapping file as default mapping could not be found.\n");
+    exit(-1);
   }
 }