Catch reverse resolve ENS errors (#7377)

The 'reverseResolveAddress' method is intended to return undefined if
unable to reverse resolve the given address. Instead it was throwing an
error, which surfaced in the UI console. This error is now caught.

app/scripts/controllers/ens/index.js

@@ -1,6 +1,7 @@
 const ethUtil = require('ethereumjs-util')
 const ObservableStore = require('obs-store')
 const punycode = require('punycode')
+const log = require('loglevel')
 const Ens = require('./ens')
 
 const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000'
@@ -51,8 +52,22 @@ class EnsController {
       return state.ensResolutionsByAddress[address]
     }
 
-    const domain = await this._ens.reverse(address)
-    const registeredAddress = await this._ens.lookup(domain)
+    let domain
+    try {
+      domain = await this._ens.reverse(address)
+    } catch (error) {
+      log.debug(error)
+      return undefined
+    }
+
+    let registeredAddress
+    try {
+      registeredAddress = await this._ens.lookup(domain)
+    } catch (error) {
+      log.debug(error)
+      return undefined
+    }
+
     if (registeredAddress === ZERO_ADDRESS || registeredAddress === ZERO_X_ERROR_ADDRESS) {
       return undefined
     }