Trim space from end of libvips error messages

src/common.h

@@ -182,6 +182,11 @@ namespace sharp {
   bool IsDzZip(std::string const &str);
   bool IsV(std::string const &str);
 
+  /*
+    Trim space from end of string.
+  */
+  std::string TrimEnd(std::string const &str);
+
   /*
     Provide a string identifier for the given image type.
   */