fix(LibReserve): fix the failure to select nearest reserve time when the max time difference is 0

The previous implementation only considered the case when more than one nearest time exists,
so we introduced the prefer_early flag to decide which one to be selected.But the comparsion
mistakenly omitted the edge case when the difference is 0.

LibReserve.py

@@ -403,9 +403,9 @@ class LibReserve(LibOperator):
                 if abs_diff < best_time_diff or (
                     abs_diff == best_time_diff and (
                         # prefer earlier time
-                        (prefer_earlier and actual_diff < 0) or
+                        (prefer_earlier and actual_diff <= 0) or
                         # prefer later time
-                        (not prefer_earlier and actual_diff > 0)
+                        (not prefer_earlier and actual_diff >= 0)
                     )
                 ):
                     best_time_diff = abs_diff