Enable syntax folding for combined diff

Author: tomtomjhj

syntax/git.vim

@@ -38,7 +38,7 @@ syn match gitReflog /^\x\{40,\} \x\{40,\} .\{-\}\d\+\s-\d\{4\}\t.*/ skipwhite c
 synregiongitDiffstart=/^\%(diff --git \)\@=/end=/^\%(diff --\|$\)\@=/contains=@gitDifffold
 synregiongitDiffstart=/^\%(@@ -\)\@=/end=/^\%(diff --\%(git\|cc\|combined\)\|$\)\@=/contains=@gitDiff
 
-synregiongitDiffMergestart=/^\%(diff --\%(cc\|combined\)\)\@=/end=/^\%(diff --\|$\)\@=/contains=@gitDiff
+synregiongitDiffMergestart=/^\%(diff --\%(cc\|combined\)\)\@=/end=/^\%(diff --\|$\)\@=/contains=@gitDifffold
 synregiongitDiffMergestart=/^\%(@@@@* -\)\@=/end=/^\%(diff --\|$\)\@=/contains=@gitDiff
 synmatchgitDiffAdded"^ \++.*"containedcontainedin=gitDiffMerge
 synmatchgitDiffAdded"{+[^}]*+}"containedcontainedin=gitDiff