[cicd] deployment to testserver, curl syntax fixed

.gitlab-ci.yml

@@ -34,7 +34,7 @@ pages-devel:
     - cp *.html .public
     - mv .public public
     - UPLOADPATH=file://$(pwd)/public
-    - curl -u tomcat:$TOMCATPASS "https://m4lab.hft-stuttgart.de/manager/text/deploy?path=/ROOT&update=true&war=$UPLOADPATH"
+    - curl -u tomcat:$TOMCATPASS "https://m4lab.hft-stuttgart.de/manager/text/deploy?path=/&update=true&war=$UPLOADPATH"
   artifacts:
     paths:
       - public