Fix GUID/PGID mismatch in 7 more app guides missed by the earlier pass

content/en/3.serveex/6.cloud/2.nextcloud.md

@@ -43,7 +43,7 @@ services:
     container_name: nextcloud
     environment:
       - PUID=${PUID}
-      - PGID=${GUID}
+      - PGID=${PGID}
       - TZ=Etc/UTC
     volumes:
       - /srv/docker/nextcloud/config:/config
@@ -60,7 +60,7 @@ If you’re using a NAS or network-shared drive via **Samba**, replace `/srv/doc
 
 ### Set your environment variables
 
-Find your `PUID` and `GUID` by running the following command:
+Find your `PUID` and `PGID` by running the following command:
 
 ```bash [Terminal]
 id username
@@ -70,7 +70,7 @@ Then fill out the `.env` file with your preferred port and the values found abov
 
 ```properties [.env]
 PUID=1000
-GUID=1000
+PGID=1000
 PORT=4545
 ```