delta navigation is broken by `--jump-target` in $LESS

I have --jump-target=.1 in my $LESS because (when using less as a pager) I like search results near the top of the screen, but with a bit of context.

However, this breaks delta's navigation, which depends on the default value of --jump-target=1.

So in my Git config, I now use:

[core]
	pager = "LESS=\"$LESS --jump-target=1\" delta --line-numbers"

When delta's navigate feature is enabled, it should call less with --jump-target=1 (overriding anything in $LESS) to restore the default.