Rebase "xuris -c" mappings to 'c'

IOW save me some broken fingers...

dotfiles/i3/config

 bindsym $mod+Return         exec "urxvt"
 bindsym $mod+Shift+Return   exec "xfce4-terminal"
 bindsym $mod+b              exec "saturnin uris -1 | head -1 | saturnin xuris -a"
-bindsym $mod+Ctrl+b         exec "saturnin uris -1 | head -1 | saturnin xuris -a -c"
+bindsym $mod+c              exec "saturnin uris -1 | head -1 | saturnin xuris -a -c"
 bindsym $mod+Shift+b        exec "saturnin uris -1 | saturnin xuris"
-bindsym $mod+Ctrl+Shift+b   exec "saturnin uris -1 | saturnin xuris -c"
+bindsym $mod+Shift+c        exec "saturnin uris -1 | saturnin xuris -c"
 bindsym $mod+i              exec "saturnin menu uris"
 bindsym $mod+Shift+i        exec "saturnin menu www_hist"
 bindsym $mod+Shift+f        exec thunar