Trying to fix a strange warning

Kingfisher.podspec

@@ -30,6 +30,7 @@ Pod::Spec.new do |s|
 
   s.source       = { :git => "https://github.com/onevcat/Kingfisher.git", :tag => s.version }
   s.source_files  = "Kingfisher/*.swift"
+  s.public_header_files = ["Kingfisher/Kingfisher.h"]
   s.requires_arc = true
   s.framework = "CFNetwork"