Add Ubuntu 24.04

- Add support for Ubuntu 24.04 LTS
  Ref: https://github.com/libreswan/libreswan/commit/46e9115

extras/vpnupgrade_ubuntu.sh

@@ -167,11 +167,13 @@ update_apt_cache() {
 }
 
 install_pkgs() {
+  p1=libcurl4-nss-dev
+  [ "$os_ver" = "trixiesid" ] && p1=libcurl4-gnutls-dev
   (
     set -x
     apt-get -yqq install libnss3-dev libnspr4-dev pkg-config \
       libpam0g-dev libcap-ng-dev libcap-ng-utils libselinux1-dev \
-      libcurl4-nss-dev libnss3-tools libevent-dev libsystemd-dev \
+      $p1 libnss3-tools libevent-dev libsystemd-dev \
       flex bison gcc make wget sed >/dev/null
   ) || exiterr2
 }

vpnsetup_ubuntu.sh

@@ -254,11 +254,13 @@ detect_ip() {
 
 install_vpn_pkgs() {
   bigecho "Installing packages required for the VPN..."
+  p1=libcurl4-nss-dev
+  [ "$os_ver" = "trixiesid" ] && p1=libcurl4-gnutls-dev
   (
     set -x
     apt-get -yqq install libnss3-dev libnspr4-dev pkg-config \
       libpam0g-dev libcap-ng-dev libcap-ng-utils libselinux1-dev \
-      libcurl4-nss-dev flex bison gcc make libnss3-tools \
+      $p1 flex bison gcc make libnss3-tools \
       libevent-dev libsystemd-dev uuid-runtime ppp xl2tpd >/dev/null
   ) || exiterr2
   if [ "$os_type" = "debian" ] && [ "$os_ver" = 12 ]; then