sip settings: fix crash when showing password

The clearTextField was garbage collected by ARC instantly after allocation,
since pointer was using (assign) == weak reference with no ownership on it.

We remove the weak reference to tryRegisterButton since it was never used.

Issue: #78366
Change-Id: Ie20dbe0adc97fba868fceaf6ad109aa67da1ca66

src/AccGeneralVC.mm

@@ -52,8 +52,7 @@
 @property (assign) IBOutlet NSTextField *serverHostTextField;
 @property (assign) IBOutlet NSTextField *usernameTextField;
 @property (assign) IBOutlet NSSecureTextField *passwordTextField;
-@property (assign) IBOutlet NSTextField *clearTextField;
-@property (assign) IBOutlet NSButton *tryRegisterButton;
+@property (strong) NSTextField *clearTextField;
 
 @property (assign) IBOutlet NSButton *upnpButton;
 @property (assign) IBOutlet NSButton *autoAnswerButton;