[uBrowser] Can not open same window on window manager

[uBrowser] Can not open same window on window manager

Problem is caused by the default behavior of list item, which sends callback
only when first becoming selected. Any further clicks will do nothing.

Solution is changing window list selection mode to
ELM_OBJECT_SELECT_MODE_ALWAYS which makes calling callback on every click
for items even if item is selected.

Reviewed by: Antonio Gomes, Janusz Majnert
Bug: http://web.sec.samsung.net/bugzilla/show_bug.cgi?id=13359
Change-Id: Ie3548f820a91366712f0d29ac340036d0631bef1