rbutil: Use a non-zero default value for status.

When resolving the status values downloaded from the server use a
negative value as default. Since 0 is the default in QSettings but now
considered as "retired" a missing status value would make that target
appear as retired instead of unknown status.

Change-Id: I23567413c5c3d5828fca7f9c5a29e2037e8614cf

rbutil/rbutilqt/base/serverinfo.cpp

@@ -115,7 +115,7 @@ void ServerInfo::readBuildInfo(QString file)
 
         info.beginGroup("status");
         QString status = tr("Unknown");
-        switch(info.value(platforms.at(i)).toInt())
+        switch(info.value(platforms.at(i), -1).toInt())
         {
             case 0:
                 status = tr("Stable (Retired)");