Fix short names of various plugins

The short_name attr must be equal the folder name of the plugin,
otherwise get_active_plugin() in PluginManager fails

juick/manifest.ini

 [info]
 name: Juick
-short_name: Juick
+short_name: juick
 version: 1.2.0
 description: Clickable Juick links , Juick nicks, preview Juick picturs.
  The key combination alt + up in the textbox allow insert the number of last message (comment or topic).

now_listen/manifest.ini

 [info]
 name: Now Listen
-short_name: now-listen
+short_name: now_listen
 version: 1.2.1
 description: Copy tune info of playing music to conversation input box at cursor position (Alt + N)
 authors = Denis Fomin <fominde@gmail.com>

pgp/manifest.ini

 [info]
 name: PGP
-short_name: PGP
+short_name: pgp
 version: 1.2.32
 description: PGP encryption as per XEP-0027
 authors: Philipp Hörist <philipp@hoerist.com>

tictactoe/manifest.ini

 [info]
 name: Tic tac toe
-short_name: Tic tac toe
+short_name: tictactoe
 version: 1.6.30
 description: Play tic tac toe
 authors = Yann Leboulanger <asterix@lagaule.org>

wrong_layout/manifest.ini

 [info]
 name: Wrong Layout
-short_name: Wrong Layout
+short_name: wrong_layout
 version: 1.2.0
 description: Press alt+r to convert chars typed in wrong layout Rus<>Eng
 authors: Denis Fomin <fominde@gmail.com>