Remove superfluous writeProject() call

We are already doing this in the line above. No need for a second
call.

Change-Id: I62e2d45691a56f0ed441eade97ae4a93d3ca446f
diff --git a/zuul/cmd/migrate.py b/zuul/cmd/migrate.py
index 3ab3902..1f0a602 100644
--- a/zuul/cmd/migrate.py
+++ b/zuul/cmd/migrate.py
@@ -1493,7 +1493,7 @@
             project_dict = self.writeProject(project)
             merge_project_dict(
                 project_dicts, project['name'],
-                self.writeProject(project))
+                project_dict)
         project_config = project_dicts_to_list(project_dicts)
 
         seen_jobs = []