Move tenant_config option to scheduler section

This is only used by the scheduler and makes more sense here.

Change-Id: I85009894fd5bd02e8795d59ea2a2612b46941718
diff --git a/tests/fixtures/zuul-git-driver.conf b/tests/fixtures/zuul-git-driver.conf
index b6d3473..4321871 100644
--- a/tests/fixtures/zuul-git-driver.conf
+++ b/tests/fixtures/zuul-git-driver.conf
@@ -1,7 +1,7 @@
 [gearman]
 server=127.0.0.1
 
-[zuul]
+[scheduler]
 tenant_config=config/zuul-connections-same-gerrit/main.yaml
 
 [merger]