feature: Rename SMTP Env variable to ADMIN

Author: irfan-ikhwa

server/api-service/lowcoder-server/src/main/resources/selfhost/ce/application.yml

@@ -19,10 +19,10 @@ spring:
   webflux:
     context-path: /
   mail:
-    host: ${LOWCODER_SMTP_HOST:smtp.gmail.com}
-    port: ${LOWCODER_SMTP_PORT:587}
-    username: ${LOWCODER_SMTP_USERNAME:yourmail@gmail.com}
-    password: ${LOWCODER_SMTP_PASSWORD:yourpass}
+    host: ${LOWCODER_ADMIN_SMTP_HOST:smtp.gmail.com}
+    port: ${LOWCODER_ADMIN_SMTP_PORT:587}
+    username: ${LOWCODER_ADMIN_SMTP_USERNAME:yourmail@gmail.com}
+    password: ${LOWCODER_ADMIN_SMTP_PASSWORD:yourpass}
 
 server:
   compression: