Removed usnused import.

Author: gmessner

src/main/java/org/gitlab4j/api/models/GroupProjectsFilter.java

@@ -2,7 +2,6 @@
 
 import org.gitlab4j.api.Constants.ProjectOrderBy;
 import org.gitlab4j.api.Constants.SortOrder;
-import org.gitlab4j.api.Constants;
 import org.gitlab4j.api.GitLabApiForm;
 
 /**