Ask for external annotation only while looking for nullability or kotlin signature annotation

idea/src/org/jetbrains/jet/plugin/codeInsight/ktSignature/KotlinSignatureUtil.java

@@ -84,7 +84,7 @@ class KotlinSignatureUtil {
     static PsiAnnotation findKotlinSignatureAnnotation(@NotNull PsiElement element) {
         if (!(element instanceof PsiModifierListOwner)) return null;
         PsiModifierListOwner annotationOwner = getAnnotationOwner(element);
-        PsiAnnotation annotation = JavaAnnotationResolver.findAnnotation(annotationOwner, KOTLIN_SIGNATURE_ANNOTATION);
+        PsiAnnotation annotation = JavaAnnotationResolver.findAnnotationWithExternal(annotationOwner, KOTLIN_SIGNATURE_ANNOTATION);
         if (annotation == null) return null;
         if (annotation.getParameterList().getAttributes().length == 0) return null;
         return annotation;