MB-5581: Revert "removed strange header magic for username = default"

This reverts commit 415b8f4.
Since default bucket has no password, we don't need to do sasl
authentication. It is the special case we need to keep it as is.

Change-Id: Ic2cf0499c251f24c9cb57fb16588be035f6b9a3f
Reviewed-on: http://review.couchbase.org/17290
Tested-by: Bin Cui <bin.cui@gmail.com>
Reviewed-by: Michael Wiederhold <mike@couchbase.com>

couchbase/rest_client.py

@@ -284,9 +284,12 @@ def _create_capi_headers(self):
 
     #authorization must be a base64 string of username:password
     def _create_headers(self):
-        authorization = base64.encodestring('%s:%s' % (self.username,
-                                                       self.password))
-        return {'Content-Type': 'application/x-www-form-urlencoded',
+        if self.username == "default":
+            return {'Content-Type': 'application/json', 'Accept': '*/*'}
+        else:
+            authorization = base64.encodestring('%s:%s' % (self.username,
+                                                self.password))
+            return {'Content-Type': 'application/x-www-form-urlencoded',
                 'Authorization': 'Basic %s' % authorization,
                 'Accept': '*/*'}