#3 Negative values are allowed for the auto update interval

[Eduard Oajdea]

The auto update interval field from the add module page allows negative values. As a result the module is never auto updated.
Steps to reproduce:
1 Go to admin portal web page
2 Input valid values for username and password
3 Press the login button
4 Press the add module link
5 Input in the name field a string
6 Input a negative number in the auto update interval input
7 Select “Local” from the dropdown input
8 Input a valid path from your file system of a directory with java files
9 Press the add button
Expected result: the page is invalidated and the auto update interval field id highlighted as invalid
Actual result: the module list is displayed and the module is never auto updated.
The logs show the following error:
Exception in thread "Thread-45" java.util.NoSuchElementException
at java.util.TreeMap.key(TreeMap.java:1206)
at java.util.TreeMap.firstKey(TreeMap.java:267)
at java.util.TreeSet.first(TreeSet.java:377)
at scse.core.Clock$ClockTask.getNextAlarmInterval(Clock.java:69)
at scse.core.Clock$ClockTask.run(Clock.java:42)
at java.lang.Thread.run(Thread.java:619)

[Eduard Oajdea]

the module list with a negative auto update interval set to a module