Improve guard so it works for no eof new line

ftplugin/latex-box/mappings.vim

@@ -1,4 +1,5 @@
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'latex') == -1
+
 " LaTeX Box mappings
 
 if exists("g:LatexBox_no_mappings")
@@ -105,4 +106,5 @@ vnoremap <buffer> <silent> [[ :<c-u>call <SID>LatexBoxNextSection(0,1,1)<CR>
 " }}}
 
 " vim:fdm=marker:ff=unix:noet:ts=4:sw=4
+
 endif