Remove scheduler parameter from connection registry

The connection registry should not have to know about the scheduler,
rather, the inverse is true.

(NB, connections themselves still know about the scheduler, but
that's okay, that happens after the connection registry is created.)

Drivers should be able to access the global configuration when
being created, so store that when the connection registry configures
itself.

Change-Id: Iea4b8fe3888b5eefd3df9ce385225b885f2caa0b
diff --git a/tests/base.py b/tests/base.py
index 736d2f7..2f77102 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -959,7 +959,7 @@
             self.sched.trigger_event_queue
         ]
 
-        self.configure_connections(self.sched)
+        self.configure_connections()
         self.sched.registerConnections(self.connections)
 
         self.ansible_server = RecordingLaunchServer(
@@ -995,7 +995,7 @@
         self.addCleanup(self.assertFinalState)
         self.addCleanup(self.shutdown)
 
-    def configure_connections(self, sched):
+    def configure_connections(self):
         # Register connections from the config
         self.smtp_messages = []
 
@@ -1009,7 +1009,7 @@
         # a virtual canonical database given by the configured hostname
         self.gerrit_changes_dbs = {}
         self.gerrit_queues_dbs = {}
-        self.connections = zuul.lib.connections.ConnectionRegistry(sched)
+        self.connections = zuul.lib.connections.ConnectionRegistry()
 
         for section_name in self.config.sections():
             con_match = re.match(r'^connection ([\'\"]?)(.*)(\1)$',