remove string unkown

app/controllers/projects_controller.rb

@@ -485,6 +485,7 @@ class ProjectsController < ApplicationController
     @trackers = Tracker.sorted.all
     @project = Project.new
     @project.safe_attributes = params[:project]
+    logger.error "=======================================================#{params[:project].class}"
     ##add by huang
     @course=Course.new
     @course.safe_attributes = params[:course]
@@ -774,7 +775,7 @@ class ProjectsController < ApplicationController
         @subPage_title = l :label_student_list
         @members = searchStudent(@project)
       else
-        @subPage_title = 'unKown'
+        @subPage_title = ''
         @members = []
       end
     else