sparse-revlog: also use sparse-revlog config as a general delta trigger

Sparse revlog rely on general delta, so we should make sure it is used.

mercurial/scmutil.py

@@ -1366,7 +1366,8 b' def gdinitconfig(ui):'
     """
     # experimental config: format.generaldelta
     return (ui.configbool('format', 'generaldelta')
-            or ui.configbool('format', 'usegeneraldelta'))
+            or ui.configbool('format', 'usegeneraldelta')
+            or ui.configbool('format', 'sparse-revlog'))
 
 def gddeltaconfig(ui):
     """helper function to know if incoming delta should be optimised