update links to main branch and remove remaning gogs links

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

README.md

@@ -2,7 +2,7 @@
 
 ### A web terminal for admins to launch Nextcloud's occ commands
 
-![occweb](https://git.adphi.net/Adphi/OCCWeb/raw/master/appinfo/screenshot.png)
+![occweb](https://github.com/Adphi/OCCWeb/raw/main/appinfo/screenshot.png)
 
 
 ## ⚠️ Deprecated ⚠️
@@ -21,4 +21,4 @@ So if your instance is pretty big, commands like `occ files:scan` will time out
 - Do not use `occ maintenance:mode --on`, obvious...
 
 ## TODOs:
-See [open issues](https://git.adphi.net/Adphi/OCCWeb/issues)
+See [open issues](https://github.com/Adphi/occweb/issues)

appinfo/info.xml

@@ -13,7 +13,7 @@
     <website>https://github.com/adphi/occweb</website>
     <bugs>https://github.com/adphi/occweb/issues</bugs>
     <repository>https://github.com/adphi/occweb</repository>
-    <screenshot>https://github.com/adphi/occweb/raw/master/appinfo/screenshot.png</screenshot>
+    <screenshot>https://github.com/adphi/occweb/raw/main/appinfo/screenshot.png</screenshot>
     <dependencies>
         <nextcloud min-version="19" max-version="27"/>
     </dependencies>