chore: small blockGamut regex fix

dist/showdown.js

@@ -1,4 +1,4 @@
-;/*! showdown 19-12-2016 */
+;/*! showdown 20-12-2016 */
 (function(){
 /**
  * Created by Tivie on 13-07-2015.
@@ -1259,8 +1259,8 @@ showdown.subParser('blockGamut', function (text, options, globals) {
   // Do Horizontal Rules:
   var key = showdown.subParser('hashBlock')('<hr />', options, globals);
   text = text.replace(/^( ?-){3,}[ \t]*$/gm, key);
-  text = text.replace(/^( ?\*){3,}[ \t]*$$/gm, key);
-  text = text.replace(/^( ?_){3,}[ \t]*$$/gm, key);
+  text = text.replace(/^( ?\*){3,}[ \t]*$/gm, key);
+  text = text.replace(/^( ?_){3,}[ \t]*$/gm, key);
 
   text = showdown.subParser('lists')(text, options, globals);
   text = showdown.subParser('codeBlocks')(text, options, globals);

src/subParsers/blockGamut.js

@@ -15,8 +15,8 @@ showdown.subParser('blockGamut', function (text, options, globals) {
   // Do Horizontal Rules:
   var key = showdown.subParser('hashBlock')('<hr />', options, globals);
   text = text.replace(/^( ?-){3,}[ \t]*$/gm, key);
-  text = text.replace(/^( ?\*){3,}[ \t]*$$/gm, key);
-  text = text.replace(/^( ?_){3,}[ \t]*$$/gm, key);
+  text = text.replace(/^( ?\*){3,}[ \t]*$/gm, key);
+  text = text.replace(/^( ?_){3,}[ \t]*$/gm, key);
 
   text = showdown.subParser('lists')(text, options, globals);
   text = showdown.subParser('codeBlocks')(text, options, globals);