Fix argument name

mmoya · mmoya · commit 2404cd5b0684 · 2015-03-17T19:14:12.000+01:00
diff --git a/prometheus_client/__init__.py b/prometheus_client/__init__.py
@@ -42,7 +42,7 @@ def register(self, collector):
     with self._lock:
       self._collectors.add(collector)
 
-  def unregister(self, metric):
+  def unregister(self, collector):
     '''Remove a collector from the registry.'''
     with self._lock:
       self._collectors.remove(collector)
