Fix adding ffmpeg to path

This fixes adding ffmpeg to the path by adding it to the user path instead of the system path, which doesn't require admin privileges to do

utils/ffmpeg_install.py

@@ -23,7 +23,7 @@ def ffmpeg_install_windows():
             os.remove(f"ffmpeg/doc/{file}")
         os.rmdir("ffmpeg/doc")
         # Add to the path
-        subprocess.run("setx /M PATH \"%PATH%;%CD%\\ffmpeg\"", shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        subprocess.run("setx PATH \"%PATH%;%CD%\\ffmpeg\"", shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         print("FFmpeg installed successfully! Please restart your computer and then re-run the program.")
         exit()
     except Exception as e:
@@ -81,4 +81,4 @@ def ffmpeg_install():
     except Exception as e:
         print("Welcome fellow traveler! You're one of the few who have made it this far. We have no idea how you got at this error, but we're glad you're here. Please report this error to the developer, and we'll try to fix it as soon as possible. Thank you for your patience!")
         print(e)
-    return None
+    return None