GWT: 0.5, Correct EN export message

Current message:

Your result has been exported in a new tabs. It is possible that 
your browser blocks popu In this case, you must grant 
permission TXMWEB site to open popu

Should be:

Your result has been exported to a new tab. Your browser may 
block popups. In this case, you should check your settings to
allow popus on the TXM Portal website. To work with the 
exported file, you should save it on your computer (Ctrl + S
or Apple + S) and open it with Excel or Calc software.

(from redmine: issue id 281, created on 2013/07/23 by Alexey Lavrentev)

added priority::high type::task + 1 deleted label

changed milestone to %Portal 0.6

OK on TEST portal

(from redmine: written on 2014/03/05 by Alexey Lavrentev)

OK BFM portal

(from redmine: written on 2014/03/11 by Alexey Lavrentev)

added time estimate of 30m

closed

assigned to @mdecorde