Also I didn't change pom.xml, tomcat-users.xml and Maven/conf/settings.xml and now all works fine.
I think your problem was the server config in your tomcat maven configuration. It conflicted with the username/password settings. In the pom.xml file you should either remove the <server>tomcat7</server> part, and keep the username and password, or remove the username and password and keep <server>tomcat7</server>.
location of setings.xml may differ, e.g. could also be: D:\apache-maven-3.3.9\conf\settings.xml
thank you, this is perfect! the server id of maven's settings.xml is corresponding to the server id in pom.xml's tomcat7-maven-plugin server id, or other way round :-) so you can define many servers and keep credentials in one place but refer from many pom.xml's to this.