Minor fix to ensure order of ICP vs cycling mode in processed config does not change on reload vs start

Author: MetRonnie

cylc/flow/config.py

@@ -685,10 +685,10 @@ def prelim_process_graph(self) -> None:
             all(item in ['graph', '1', 'R1'] for item in graphdict)
         ):
             # Pure acyclic graph, assume integer cycling mode with '1' cycle
-            self.cfg['scheduling']['cycling mode'] = INTEGER_CYCLING_TYPE
             for key in ('initial cycle point', 'final cycle point'):
                 if key not in self.cfg['scheduling']:
                     self.cfg['scheduling'][key] = '1'
+            self.cfg['scheduling']['cycling mode'] = INTEGER_CYCLING_TYPE
 
     def process_utc_mode(self):
         """Set UTC mode from config or from stored value on restart.