remove support for inactive modified

statuslines don't actually get evaluated in inactive splits, so this feature never worked properly anyways.

autoload/airline/themes/solarized.vim

@@ -125,9 +125,6 @@ function! s:generate()
         \ [s:IA[0].g, s:IA[1].g, s:IA[0].t, s:IA[1].t, s:IA[2]],
         \ s:NFa)
 
-  let g:airline#themes#solarized#inactive_modified = {
-        \ 'statusline': [s:NM.statusline[0].g, '', s:NM.statusline[0].t, '', ''] }
-
   let g:airline#themes#solarized#normal = airline#themes#generate_color_map(
         \ [s:N1[0].g, s:N1[1].g, s:N1[0].t, s:N1[1].t, s:N1[2]],
         \ [s:N2[0].g, s:N2[1].g, s:N2[0].t, s:N2[1].t, s:N2[2]],