tmux: Remove statusline time and date

Removed display of time and date from tmux, since I have the polybar
time up always.

Shuffled around the rest of the display: removed left-sided display of
active (tmux) user, moved it to the right side.

nvim/.config/nvim/plugin/tmuxline.vim

@@ -2,11 +2,9 @@
 " PLUGIN: TMUXLINE
 let g:tmuxline_preset = {
   \'a'       : '#S',
-  \'b'       : '#(whoami)',
-  \'c'       : '#I:#P',
+  \'b'       : '#I:#P',
   \'win'     : '#I #W',
   \'cwin'    : [' ', '#I #W'],
-  \'x'       : '#{?client_prefix,#[fg=colour232]#[bg=brightblue],} %H:%M:%S',
-  \'y'       : '%d-%b-%y',
+  \'y'       : '#{?client_prefix,#[fg=colour232]#[bg=brightblue],} #(whoami)',
   \'z'       : '#H',
   \'options' : {}}