Make strings identical

src/backend/utils/adt/rangetypes.c

@@ -1902,7 +1902,7 @@ range_parse_flags(const char *flags_str)
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
 					 errmsg("invalid range bound flags"),
-				   errhint("Valid values are '[]', '[)', '(]', and '()'.")));
+				 errhint("Valid values are \"[]\", \"[)\", \"(]\", and \"()\".")));
 	}
 
 	switch (flags_str[1])
@@ -1916,7 +1916,7 @@ range_parse_flags(const char *flags_str)
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
 					 errmsg("invalid range bound flags"),
-				   errhint("Valid values are '[]', '[)', '(]', and '()'.")));
+				 errhint("Valid values are \"[]\", \"[)\", \"(]\", and \"()\".")));
 	}
 
 	return flags;