Removed extern "C" from threadEntryProc

modules/juce_core/native/juce_posix_SharedCode.h

@@ -887,8 +887,7 @@ void JUCE_API juce_threadEntryPoint (void*);
 extern JavaVM* androidJNIJavaVM;
 #endif
 
-extern "C" void* threadEntryProc (void*);
-extern "C" void* threadEntryProc (void* userData)
+static void* threadEntryProc (void* userData)
 {
     auto* myself = static_cast<Thread*> (userData);