t/t5NNN: allow local submodules

To prepare for the default value of `protocol.file.allow` to change to
"user", ensure tests that rely on local submodules can initialize them
over the file protocol.

Tests that only need to interact with submodules in a limited capacity
have individual Git commands annotated with the appropriate
configuration via `-c`. Tests that interact with submodules a handful of
times use `test_config_global` instead. Test scripts that rely on
submodules throughout use a `git config --global` during a setup test
towards the beginning of the script.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
diff --git a/t/t5545-push-options.sh b/t/t5545-push-options.sh
index 38e6f73..77ce917 100755
--- a/t/t5545-push-options.sh
+++ b/t/t5545-push-options.sh
@@ -113,6 +113,7 @@
 	test_commit -C parent one &&
 	git -C parent push --mirror up &&
 
+	test_config_global protocol.file.allow always &&
 	git -C parent submodule add ../upstream workbench &&
 	git -C parent/workbench remote add up ../../upstream &&
 	git -C parent commit -m "add submodule" &&