fix: report info-flag should not error when app undeployed

Several plugin `:report` subcommands erroneously failed with `not deployed` when an info-flag matched a property that was empty. Empty values are legitimate for configuration properties pre-deploy and the `--format json` path already returns them without error. Remove the `value_exists` check across nginx, checks, git, certs, scheduler-docker-local, and the builder-* plugins so the info-flag form behaves consistently with the JSON form.

tests/unit/certs.bats

@@ -41,6 +41,25 @@ teardown() {
   assert_output "$help_output"
 }
 
+@test "(certs:report) info-flag works before deploy" {
+  run /bin/bash -c "dokku certs:report $TEST_APP --ssl-hostnames"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+  run /bin/bash -c "dokku certs:report $TEST_APP --ssl-dir"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains "/$TEST_APP/tls"
+
+  run /bin/bash -c "dokku certs:report $TEST_APP --ssl-invalid-flag"
+  echo "output: $output"
+  echo "status: $status"
+  assert_failure
+  assert_output_contains "Invalid flag passed"
+}
+
 @test "(certs:report) --global --format json" {
   run /bin/bash -c "dokku certs:report --global --format json | jq -e ."
   echo "output: $output"