Add support for BDB 4.6.
diff --git a/configure.ac b/configure.ac
index 99dc39d..92cd421 100644
--- a/configure.ac
+++ b/configure.ac
@@ -43,8 +43,9 @@
 dnl Checks for required libraries
 dnl -----------------------------
 AC_CHECK_LIB(db-4.5, db_create, DB_LIBS=-ldb-4.5,
+	AC_CHECK_LIB(db-4.6, db_create, DB_LIBS=-ldb-4.6,
 	AC_CHECK_LIB(db-4.4, db_create, DB_LIBS=-ldb-4.4,
-	AC_CHECK_LIB(db-4.3, db_create, DB_LIBS=-ldb-4.3, exit 1)))
+	AC_CHECK_LIB(db-4.3, db_create, DB_LIBS=-ldb-4.3, exit 1))))
 AC_CHECK_LIB(crypto, SHA1_Update, CRYPTO_LIBS=-lcrypto, exit 1)
 
 dnl -------------------------------------