Fixing a typo

And now we have a working xitter client.

Yes this is why it didn't work. Let it be a lesson (of what? I don't
know).

exitter.el

@@ -320,7 +320,7 @@
           (replace-regexp-in-string
            "&" "%26"
            (replace-regexp-in-string
-            "=" "%3d"
+            "=" "%3D"
             (replace-regexp-in-string
              "%" "%25"
              (replace-regexp-in-string