[FIX] assert that only 1 class is found for a model in a backend
[FIX] assert that only 1 class is found for a model in a backend

sylvain-garancher/connector,Antiun/connector,BT-jmichaud/connector,dvitme/connector,mohamedhagag/connector,esousy/connector,Endika/connector,anybox/connector,BT-fgarbely/connector,MindAndGo/connector,brain-tec/connector,BT-ojossen/connector,maljac/connector,gurneyalex/connector,BT-ojossen/connector,esousy/connector,zhaohuaw/connector,open-synergy/connector,acsone/connector,acsone/connector,open-synergy/connector,mohamedhagag/connector,gurneyalex/connector,dvitme/connector,hugosantosred/connector,guewen/connector,BT-jmichaud/connector,anybox/connector,zhaohuaw/connector,maljac/connector,MindAndGo/connector,acsone/connector,fevxie/connector,hugosantosred/connector,Antiun/connector,sylvain-garancher/connector,js-landoo/connector,Endika/connector,brain-tec/connector,brain-tec/connector,js-landoo/connector,guewen/connector,fevxie/connector,BT-fgarbely/connector