Fix error popup when --launch-game is used

gmutils.py

@@ -1,6 +1,7 @@
 import json
 import os
 import subprocess
+import sys
 
 import customtkinter
 import requests
@@ -45,7 +46,7 @@ def check_files():
             # print("displayz.exe downloaded")
         except Exception as e:
             popup("Error", f"Could not download required file displayz.exe. Submit an issue to the GitHub if you believe this is a bug:\n\n {e}")
-            exit(0)
+            sys.exit(0)
     if not os.path.isfile("settings.json"):
         with open("settings.json", "w") as f:
             f.write('{"default_monitor": 0, "games": []}')

main.py

@@ -256,7 +256,7 @@ def launch_game(game_name):
                 time.sleep(2)
         os.system(game_name)
         set_monitor(default_monitor)
-        exit(0)
+        sys.exit(0)
     else:
         for game in games:
             if game.get("name") == game_name:
@@ -265,7 +265,7 @@ def launch_game(game_name):
                 os.chdir(os.path.dirname(game.get('path')))
                 os.system(f"\"{game.get('process_name')}\"")
                 set_monitor(default_monitor)
-                exit(0)
+                sys.exit(0)
 
 
 def load_games(window):
@@ -316,6 +316,8 @@ def main(open_window):
                 launch_game(sys.argv[i + 1])
 
         main(show_on_startup)
+    except SystemExit:
+        pass
     except Exception as e:
         popup("Error", f"An error occurred. If you believe this to be a bug, please submit an issue at github.com/supercam19/GameMonitor/issues with the error message:\n\n{e}")