gitignore: compile_commands.json

This file is generated by "make vim-ide-integration"

Change-Id: I9355bc36b2a654efd6183b268662b10b224f2117
Reviewed-on: https://gerrit.libreoffice.org/39108Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

.gitignore

@@ -171,3 +171,6 @@ LibreOffice.VC.VC.opendb
 # Sublime Specific
 *.sublime-project
 *.sublime-workspace
+
+# vim-ide-integration
+compile_commands.json