git: Add indent-with-non-tab to core.whitespace

The rest was already enabled by default.

.config/git/config

@@ -56,6 +56,7 @@
 	#pager = delta
 	pager = diff-so-fancy \
 	        | less --tabs=8 --RAW-CONTROL-CHARS --quit-if-one-screen
+	whitespace = trailing-spaces,space-before-tab,indent-with-non-tab
 [delta]
 	navigate = true
 	commit-decoration-style = bold yellow box