fix(tabs ios): Setting unselected color crashes app

[Logikgate]

Setting the un-selected-item-color caused apps to crash with the below output. This fixes it 😄

file: mobile/src/tabs.ios.ts:1001:85: JS ERROR TypeError: undefined is not an object (evaluating 'this._selectedItemColor.ios')
NativeScript caught signal 11.
Native Stack:
1   0x1084f2171 sig_handler(int)
2   0x10e7225fd _sigtramp
3   0x12abf0000
4   0x10e660b4d libunwind::UnwindCursor<libunwind::LocalAddressSpace, libunwind::Registers_x86_64>::step()
5   0x10e664e4c _Unwind_RaiseException
6   0x10e2404aa __cxa_throw
7   0x10ca49bfa _objc_exception_destructor(void*)
8   0x1084a1b6f NativeScript::reportFatalErrorBeforeShutdown(JSC::ExecState*, JSC::Exception*, bool)
9   0x1084e23a8 NativeScript::FFICallback<NativeScript::ObjCMethodCallback>::ffiClosureCallback(ffi_cif*, void*, void**, void*)
10  0x108eddc90 ffi_closure_unix64_inner
11  0x108ede6b2 ffi_closure_unix64
12  0x10ec59ba2 -[UIViewController __viewWillAppear:]
13  0x10eba2491 -[UINavigationController _startCustomTransition:]
14  0x10ebb831a -[UINavigationController _startDeferredTransitionIfNeeded:]
15  0x10ebb96a7 -[UINavigationController __viewWillLayoutSubviews]
16  0x10eb9a38d -[UILayoutContainerView layoutSubviews]
17  0x10f7239c1 -[UIView(CALayerDelegate) layoutSublayersOfLayer:]
18  0x10b7f5eae -[CALayer layoutSublayers]
19  0x10b7fab88 CA::Layer::layout_if_needed(CA::Transaction*)
20  0x10b806ee4 CA::Layer::layout_and_display_if_needed(CA::Transaction*)
21  0x10b7763aa CA::Context::commit_transaction(CA::Transaction*)
22  0x10b7ad584 CA::Transaction::commit()
23  0x10b7adede CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*)
24  0x10db5b0f7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__
25  0x10db555be __CFRunLoopDoObservers
26  0x10db55c31 __CFRunLoopRun
27  0x10db55302 CFRunLoopRunSpecific
28  0x1142e62fe GSEventRunModal
29  0x10f255ba2 UIApplicationMain
30  0x108ede4f5 ffi_call_unix64
31  0x1338c7560
JS Stack:
UIApplicationMain([native code])
at run(file: mobile/packages/core/application/index.ios.ts:398:20)
at file: node_modules/nativescript-vue/dist/index.js:12403:23
at file:///app/bundle.js:37627:10
at ./main.ts(file:///app/bundle.js:37632:34)
at __webpack_require__(file: mobile/webpack/bootstrap:74:0)
at checkDeferredModules(file: mobile/webpack/bootstrap:43:0)
at webpackJsonpCallback(file: mobile/webpack/bootstrap:30:0)
at anonymous(file:///app/bundle.js:2:61)
at evaluate([native code])
at moduleEvaluation
at
at asyncFunctionResume
at
at promiseReactionJob

[farfromrefug]

@Logikgate thanks a lot and sorry for the issue

[Logikgate]

@farfromrefug No problem, thanks for the quick merge 🎉