Make OhMyGlb operator watch all namespaces for Gslb CRs

[ytsarev]

• Operator is cluster scope
• Gslb CRDs are namespaced

[ytsarev]

Before we operated default namespaced scenario of operator-sdk: operator was managing resources in the same namespace as own deployment. OhMyGlb needs to watch all namespaces as there can be multiple application teams in different namespaces managing own Gslb resources.
Excerpt from operator log after this change:

{"level":"info","ts":1576684481.7743516,"logger":"controller-runtime.controller","msg":"Starting workers","controller":"gslb-controller","worker count":1}
{"level":"info","ts":1576684481.77468,"logger":"controller_gslb","msg":"Reconciling Gslb","Request.Namespace":"default","Request.Name":"example-gslb"}
{"level":"info","ts":1576684482.086346,"logger":"controller_gslb","msg":"Reconciling Gslb","Request.Namespace":"test","Request.Name":"example-gslb"}

It's visible that example-gslb got reconciled in both default and test namespaces