refactor: change variable names

Signed-off-by: Bart Jaskulski <bjaskulski@protonmail.com>

includes/deploy/demo.yml

 deploy:demo:
   image: gitlab.wpdesk.dev:5050/wpdesk/docker-tests/amazon-svn-deploy:24.09
   variables:
-    DEPLOY_TARGETS:
+    DEMO_DEPLOY_TARGETS:
       value: "demo.wpdesk.org,demo.wpdesk.pl"
       description: "Override this variable in project's .gitlab-ci.yml to support other servers. List supported targets separated by `,`. You may also use short name for deploy target, like \"wpdesk,octolize\" to support both wpdesk and both octolize targets. Currently supported targets: demo.wpdesk.org, demo.wpdesk.pl, demo.octolize.com, stage.demo.octolize.com, demo.flexibleinvoices."
   environment:
@@ -28,7 +28,7 @@ deploy:demo:
     - if: $CI_COMMIT_TAG == null
       when: never
     # Omit if server is not in deploy targets
-    - if: $DEPLOY_SERVER !~ $DEPLOY_TARGETS
+    - if: $DEPLOY_SERVER !~ $DEMO_DEPLOY_TARGETS
       when: never
     # Specific server overrides
     ## demo.wpdesk.pl
@@ -46,13 +46,13 @@ deploy:demo:
       variables:
         SSH_DSN: wlgmnfabmq@s125.cyber-folks.pl:/home/wlgmnfabmq/domains/demo.octolize.com/public_html/wp-content/plugins
         SSH_PORT: 222
-        GLOBAL_SSH_PRIV_KEY: $DEMO_FS_SSH_KEY
+        GLOBAL_SSH_PRIV_KEY: $DEMO_FS_SSH_KEY_FILE
     ## stage.demo.octolize.com
     - if: $DEPLOY_SERVER == 'stage.demo.octolize.com'
       variables:
         SSH_DSN: wlgmnfabmq@s125.cyber-folks.pl:/home/wlgmnfabmq/domains/stage.demo.octolize.com/public_html/wp-content/plugins
         SSH_PORT: 222
-        GLOBAL_SSH_PRIV_KEY: $DEMO_FS_SSH_KEY
+        GLOBAL_SSH_PRIV_KEY: $DEMO_FS_SSH_KEY_FILE
     ## demo.flexibleinvoices.com
     - if: $DEPLOY_SERVER == 'demo.flexibleinvoices.com'
       variables: