Do not remove Wimax as connection type from enums

This need to be synced with NMQT::ConnectionSettings, otherwise we are
comparing different connection types

BUG: 386171

libs/declarative/enums.h

@@ -55,6 +55,7 @@ public:
         Pppoe,
         Vlan,
         Vpn,
+        Wimax,
         Wired,
         Wireless
     };