Remove check for license blob in linter

Closes #3909

test/lint.js

@@ -3,8 +3,7 @@ var blint = require("blint");
 ["mode", "lib", "addon", "keymap"].forEach(function(dir) {
   blint.checkDir(dir, {
     browser: true,
-    allowedGlobals: ["CodeMirror", "define", "test", "requirejs"],
-    blob: "// CodeMirror, copyright (c) by Marijn Haverbeke and others\n// Distributed under an MIT license: http:\/\/codemirror.net\/LICENSE\n\n"
+    allowedGlobals: ["CodeMirror", "define", "test", "requirejs"]
   });
 });