[DBD::Pg] Fix building on pre-5.18 perls

Committed by =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <[email protected]>

Fix building on pre-5.18 perls

isALPHANUMERIC_A was introduced in 5.18, so use the expanded version
for backwards compatibility.
---
 dbdimp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dbdimp.c b/dbdimp.c
index 2dee5d4..1bf5227 100644
--- a/dbdimp.c
+++ b/dbdimp.c
@@ -2958,7 +2958,7 @@ static void pg_db_detect_client_encoding_utf8(pTHX_ imp_dbh_t *imp_dbh) {
 	Newx(clean_encoding, len + 1, char);
 	for (i = 0, j = 0; i < len; i++) {
 		const char c = toLOWER(client_encoding[i]);
-		if (isALPHANUMERIC_A(c))
+		if (isALPHA(c) || isDIGIT(c))
 			clean_encoding[j++] = c;
 	};
 	clean_encoding[j] = '\0';
-- 
1.8.4