Correct the comparison for given color codes
Correct the comparison for given color codes

this issue fixes #758

The problem was, that a given color list ['','',0,'',''] was given to
the airline#highlighter#exec() function. This resulted in the following
comparison:

if (get(colors,2,'') != '')  ? 'ctermfg='.colors[2] : ''

which, since echo 0 != '' returns falls will return a single:

:hi group

and no color codes given and therefore, Vim would output the
current highlighting group.

Use isnot# as comparison to fix this issue.

blueyed/vim-airline,tschundler/dotfiles,yzhou61/vim-airline,wilywampa/vim-airline,unphased/vim-airline,mildred/vim-airline,HarmtH/vim-airline,rchicoli/vim-airline,sappo/vim-airline,tschundler/dotfiles,chrisbra/vim-airline,vim-IDE/vim-airline,tschundler/dotfiles,dalguji/vim-airline,bling/vim-airline