fix: ignore client_target_release if not available (debug mode)

Author: Michael Weibel

helio_blender_addon/addon.py

@@ -257,7 +257,11 @@ def process_step(self, context):
         elif action == 'open_client':
             protocol = "helio-render"
             prefs = addon_updater_ops.get_user_preferences(context)
-            release = prefs.client_target_release
+            try:
+                release = prefs.client_target_release
+            except AttributeError:
+                release = "ALPHA"
+
             if release == "BETA":
                 protocol += "-beta"
             elif release == "ALPHA":