Remove implicit initialization of all maxscales

The extra maxscale instances are only started if the test explicitly
requests it.

maxscale-system-test/keepalived.cpp

@@ -22,6 +22,7 @@ int main(int argc, char *argv[])
 
     char * version;
 
+    TestConnections::multiple_maxscales(true);
     TestConnections * Test = new TestConnections(argc, argv);
     Test->set_timeout(10);