use the lock everywhere

modules/active_modifier.py

@@ -61,9 +61,10 @@ class Module(ActiveModifier):
 
             if not self.originals or self.originals[-1] != track: self.originals.append(track)
 
-            with open("/tmp/radioPlayer_toplay", "w") as f:
-                f.write('\n'.join(songs))
-                f.write("\n")
+            with self.file_lock:
+                with open("/tmp/radioPlayer_toplay", "w") as f:
+                    f.write('\n'.join(songs))
+                    f.write("\n")
 
             logger.info(f"Playing {song.name} instead, as instructed by toplay")