Bug#14547952: DEBUG BUILD FAILS ASSERTION IN RECORDS_IN_RANGE()

ha_innobase::records_in_range(): Remove a debug assertion
that prohibits an open range (full table).
This assertion catches unnecessary calls to this method, 
but such calls are not harming correctness.

storage/innobase/handler/ha_innodb.cc

@@ -6380,7 +6380,6 @@ ha_innobase::records_in_range(
 	void*		heap2;
 
 	DBUG_ENTER("records_in_range");
-	DBUG_ASSERT(min_key || max_key);
 
 	ut_a(prebuilt->trx == thd_to_trx(ha_thd()));