merge datso#219 to support RN 0.60+

Author: TristaTel25

react-native-pjsip.podspec

@@ -17,4 +17,8 @@ Pod::Spec.new do |s|
 
   s.dependency 'React'
   s.vendored_frameworks = 'ios/VialerPJSIP.framework'
+  s.xcconfig = {
+    'GCC_PREPROCESSOR_DEFINITIONS' => 'PJ_AUTOCONF=1',
+    'USE_HEADERMAP' => 'NO',
+  }
 end