Added new text in message properties file.
Added Message when no students were joined.
Merge remote-tracking branch 'upstream/dev-branch' into dev-branch

* upstream/dev-branch:
  Share Url issue resolved
  added background for popup
  Removed itemseq taking from API and rectified issue with re-order.
  score hedging view issue for Itemsequence value
  Fixed reorder issue
  Due date field validation has been implemented.
  "unit name junking on hover issue fixed"
  Modified and added new messages in MessageProperty file
  reseting unit assignment view functionality issue has been fixed.
  classsetup load issues resolved
  More Units Item sequence issue resolved

Conflicts:
	src/main/java/org/ednovo/gooru/shared/i18n/MessageProperties.java
	src/main/java/org/ednovo/gooru/shared/i18n/MessageProperties.properties
Merge pull request #1757 from anilgooru/dev-branch

Added new text in message properties file.