Fix code cyclomatic complexity

Author: amanakin

client.go

@@ -115,12 +115,12 @@ func NewClient(config *ClientConfig) (*Client, error) {
 
 	if len(config.TURNServerAddr) > 0 {
 		turnServ, err = config.Net.ResolveUDPAddr("udp4", config.TURNServerAddr)
-		if err != nil {
-			if !config.IgnoreTURNResolveErrors {
-				return nil, err
-			}
+		switch {
+		case err != nil && !config.IgnoreTURNResolveErrors:
+			return nil, err
+		case err != nil && config.IgnoreTURNResolveErrors:
 			log.Debugf("Failed to resolve TURN server %s: %s", config.TURNServerAddr, err)
-		} else {
+		case err == nil:
 			log.Debugf("Resolved TURN server %s to %s", config.TURNServerAddr, turnServ)
 		}
 	}