drg-xmrig 6.25.1-drg2: fix default pool port (3433) and algo

The bundled config had a portless pool URL (pool.dragonx.is), so xmrig
fell back to its default port 3333, which is firewalled on the pool host
-> repeating 'connect error: operation canceled'. The pool's stratum is
plain TCP on 3433 and requires a shielded zs-address worker name.

- src/config.example.json: url -> pool.dragonx.is:3433, algo -> rx/dragonx,
  user placeholder -> YOUR_DRGX_ZS_ADDRESS
- scripts/pool_mine_example.cmd: point at the DragonX pool with rx/dragonx
- scripts/build_windows.sh: fetch OpenSSL 1.1.1w from GitHub release mirror
- bump APP_VERSION to 6.25.1-drg2

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/build_windows.sh

@@ -33,7 +33,7 @@ if [ ! -f "$DEPS_DIR/lib/libssl.a" ]; then
     cd "$DEPS_DIR"
     
     if [ ! -f "openssl-${OPENSSL_VERSION}.tar.gz" ]; then
-        wget "https://openssl.org/source/old/1.1.1/openssl-${OPENSSL_VERSION}.tar.gz"
+        wget "https://github.com/openssl/openssl/releases/download/OpenSSL_1_1_1w/openssl-${OPENSSL_VERSION}.tar.gz"
     fi
     
     if [ ! -d "openssl-${OPENSSL_VERSION}" ]; then