update readme as IT tests are running per default now (#8139)

Author: olamy

jetty-maven-plugin/README_INTEGRATION_TEST.md

@@ -8,10 +8,6 @@ Integration tests location
 --------------------
 Test projects are located within the folder: src/it
 
-Running the tests
---------------------
-As they can be long to run, the tests do not run per default. So to run them you must activate a profile using the command line argument: ```-Prun-its``` 
-
 Running single test
 --------------------
 You can run single or set of test as well using the command line argument: ```-Dinvoker.test=it-parent-pom,jetty-run-mojo-it,jetty-run-war*-it,!jetty-run-distro*```