simplify logic and avoid panics

api/agent.go

@@ -400,14 +400,14 @@ func NewControllerWrapper(config *loadtest.Config, controllerConfig interface{},
 			// Check if the user has a custom authentication type. Custom authentication types are
 			// specified by prepending the username with the authentication type followed by a colon.
 			// Example: "openid:[email protected] user1password"
-			if strings.Contains(username, ":") {
-				usernameParts := strings.Split(username, ":")
+			if usernameParts := strings.Split(username, ":"); len(usernameParts) > 1 {
 				authenticationType = usernameParts[0]
 				username = usernameParts[1]
 
 				// Fix the email as well
-				emailParts := strings.Split(email, ":")
-				email = emailParts[1]
+				if emailParts := strings.Split(email, ":"); len(emailParts) > 1 {
+					email = emailParts[1]
+				}
 			}
 		}