Update lib/rdoc/markup/heading.rb

Co-authored-by: Stan Lo <[email protected]>

Author: ioquatix

lib/rdoc/markup/heading.rb

@@ -68,8 +68,8 @@ def label context = nil
   def plain_html
     text = self.text.dup
 
-    if text.match?(/rdoc-image:[^:]+:(.*)/)
-      text = text.match(/rdoc-image:[^:]+:(.*)/)[1]
+    if matched = text.match(/rdoc-image:[^:]+:(.*)/)
+      text = matched[1]
     end
 
     self.class.to_html.to_html(text)