feat(vpn): VPN_ENDPOINT_IP

- Deprecate `OPENVPN_TARGET_IP`
- Deprecate `WIREGUARD_ENDPOINT_IP`

Dockerfile

@@ -68,6 +68,8 @@ LABEL \
     org.opencontainers.image.description="VPN swiss-knife like client to tunnel to multiple VPN servers using OpenVPN, IPtables, DNS over TLS, Shadowsocks, an HTTP proxy and Alpine Linux"
 ENV VPNSP=pia \
     VPN_TYPE=openvpn \
+    # Common VPN options
+    VPN_ENDPOINT_IP= \
     # OpenVPN
     OPENVPN_PROTOCOL=udp \
     OPENVPN_USER= \
@@ -80,7 +82,6 @@ ENV VPNSP=pia \
     OPENVPN_CIPHER= \
     OPENVPN_AUTH= \
     OPENVPN_PROCESS_USER= \
-    OPENVPN_TARGET_IP= \
     OPENVPN_IPV6=off \
     OPENVPN_CUSTOM_CONFIG= \
     OPENVPN_INTERFACE=tun0 \
@@ -90,7 +91,6 @@ ENV VPNSP=pia \
     WIREGUARD_PRESHARED_KEY= \
     WIREGUARD_PUBLIC_KEY= \
     WIREGUARD_ADDRESS= \
-    WIREGUARD_ENDPOINT_IP= \
     WIREGUARD_ENDPOINT_PORT= \
     WIREGUARD_INTERFACE=wg0 \
     # VPN server filtering