Replace config/project repos with config/untrusted projects

The config-repo / project-repo terminology is confusing and we've
generally been using trusted-project and untrusted-project instead.
The term "untrusted-project" is straightforward, but "trusted-project"
is a little misleading, since there are other characteristics which
define it (notably, that the configuration held in it is branchless).
A better term for that might be "config-project".

Since the main config now directly refers to projects rather than
repos, complete the transition by replacing all config-repo
occurances with config-project and likewise project-repo with
untrusted-project.

Change-Id: I2341aa94e3622e2647b0506b78bc84dbcdec1901
Story: 2000953
diff --git a/zuul/manager/__init__.py b/zuul/manager/__init__.py
index 9661f54..0c48e9a 100644
--- a/zuul/manager/__init__.py
+++ b/zuul/manager/__init__.py
@@ -487,14 +487,14 @@
             loader.createDynamicLayout(
                 item.pipeline.layout.tenant,
                 build_set.files,
-                include_config_repos=True)
+                include_config_projects=True)
 
             # Then create the config a second time but without changes
             # to config repos so that we actually use this config.
             layout = loader.createDynamicLayout(
                 item.pipeline.layout.tenant,
                 build_set.files,
-                include_config_repos=False)
+                include_config_projects=False)
         except zuul.configloader.ConfigurationSyntaxError as e:
             self.log.info("Configuration syntax error "
                           "in dynamic layout %s" %