Removed unused code

Author: Nicholas C. Zakas

encodings/base64/base64.js

@@ -101,7 +101,7 @@ function base64Decode(text){
 
         switch(digitNum){
 
-            //case 0: do nothing, not enough info to work with
+            //case 0: first digit - do nothing, not enough info to work with
 
             case 1: //second digit
                 result.push(String.fromCharCode(prev << 2 | cur >> 4));