Do not return promise for synchronous load call

Even if there are a pending promise, synchronous call should always return the
field.

issue11273
review366781003
(grafted from 0461c402cba7f292c7a78f47ac55a671214c8388)

--HG--
branch : 6.0

src/model.js

@@ -665,7 +665,7 @@
                     return;
                 }
             }
-            if (this.group.prm.state() == 'pending') {
+            if (async && this.group.prm.state() == 'pending') {
                 return this.group.prm.then(function() {
                     return this.load(name);
                 }.bind(this));