Utils::NetworkAccessManager: Fix typo in generic unix case.

Change-Id: I25d11af5bff0cca3ed6f0bf2f11e928c4e75a423
Reviewed-on: http://codereview.qt.nokia.com/1903
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>

src/libs/utils/networkaccessmanager.cpp

@@ -111,7 +111,7 @@ static const QString getOsString()
         osString += QLatin1String("Unix (Unknown)");
     }
 #else
-    ossttring = QLatin1String("Unknown OS");
+    osString = QLatin1String("Unknown OS");
 #endif
     return osString;
 }