REGRESSION (263465@main) Crash when scrolling on Twitter.com

https://bugs.webkit.org/show_bug.cgi?id=256098
rdar://108666748

Reviewed by Wenson Hsieh.

263465@main dropped an isEmpty() checks for the languages vector and this
caused an out-of-bounds accesses later on.

* Source/WebKit/GPUProcess/GPUProcess.cpp:
(WebKit::GPUProcess::initializeGPUProcess):

Canonical link: https://commits.webkit.org/263512@main

Source/WebKit/GPUProcess/GPUProcess.cpp

@@ -280,7 +280,9 @@ void GPUProcess::initializeGPUProcess(GPUProcessCreationParameters&& parameters)
     WTF::Thread::setCurrentThreadIsUserInteractive(0);
 
     WebCore::setPresentingApplicationPID(parameters.parentPID);
-    overrideUserPreferredLanguages(parameters.overrideLanguages);
+
+    if (!parameters.overrideLanguages.isEmpty())
+        overrideUserPreferredLanguages(parameters.overrideLanguages);
 
 #if USE(OS_STATE)
     registerWithStateDumper("GPUProcess state"_s);