remove -D on server add

cli/server/add.go

@@ -116,16 +116,10 @@ If "--local" is passed, then Abra assumes that the current local server is
 intended as the target server. This is useful when you want to have your entire
 Co-op Cloud config located on the server itself, and not on your local
 developer machine. The domain is then set to "default".
-
-You can also pass "--no-domain-checks/-D" flag to use any arbitrary name
-instead of a real domain. The host will be resolved with the "Hostname" entry
-of your ~/.ssh/config. Checks for a valid online domain will be skipped:
-
-  abra server add -D example`,
+`,
 	Flags: []cli.Flag{
 		internal.DebugFlag,
 		internal.NoInputFlag,
-		internal.NoDomainChecksFlag,
 		localFlag,
 	},
 	Before:    internal.SubCommandBefore,
@@ -170,10 +164,8 @@ of your ~/.ssh/config. Checks for a valid online domain will be skipped:
 			return nil
 		}
 
-		if !internal.NoDomainChecks {
 		if _, err := dns.EnsureIPv4(name); err != nil {
-				log.Fatal(err)
-			}
+			log.Warn(err)
 		}
 
 		_, err := createServerDir(name)