Delete ng-attributes.txt

that file makes no sense anymore cause of this https://github.com/JetBrains/intellij-plugins/commit/d9d0e96d2d5ae0f985449870212b085c2f5d3468
#WEB-10981 fixed
Merge branch 'patch-1' of https://github.com/chicoxyzzy/intellij-plugins
Merge branch 'master' of git.labs.intellij.net:idea/contrib
#WEB-10986 fixed