openvpn: remove unrecognized option

removed upstream in
9ffd00e754
now its always on

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

package/network/services/openvpn/Makefile

@@ -73,7 +73,6 @@ define Build/Configure
 		--disable-plugins \
 		--disable-debug \
 		--disable-pkcs11 \
-		--enable-password-save \
 		$(if $(CONFIG_OPENVPN_$(BUILD_VARIANT)_ENABLE_LZO),--enable,--disable)-lzo \
 		$(if $(CONFIG_OPENVPN_$(BUILD_VARIANT)_ENABLE_X509_ALT_USERNAME),enable,disable-x509-alt-username)-ssl \
 		$(if $(CONFIG_OPENVPN_$(BUILD_VARIANT)_ENABLE_SERVER),--enable,--disable)-server \