#572 Patch for bug #3913 (beanshell do-while loop bug)

[Jesse Pavel]

Bug report: https://sourceforge.net/p/jedit/bugs/3913/

It would be good to integrate some (more) of the BeanShell2 improvements, but I think this bug is the most egregious, liable to cause infinite loops if the user is unaware and stumbles upon it. I've attached a patch against SVN (rev 24097) that contains the fix.

[Eric Le Lay]

applied in [r24162].
Thanks for the patch :-)