fixed Pahlavi Iran flag not showing in game (#2469)

If this PR fixes an issue, link it below. If not, delete these two
lines.
Resolves #(issue number)

## Description:

Describe the PR.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

DISCORD_USERNAME

src/client/data/countries.json

@@ -979,6 +979,11 @@
     "continent": "Asia",
     "name": "Iran"
   },
+  {
+    "code": "Pahlavi Iran",
+    "continent": "Asia",
+    "name": "Pahlavi Iran"
+  },
   {
     "code": "ie",
     "continent": "Europe",