ci: remove clause for Ubuntu 16.04

We're no longer testing this version and it's well beyond regular LTS
support now, so remove the stanza for it from the case statement in our
CI code.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

Author: bk2204

ci/install-dependencies.sh

@@ -55,11 +55,6 @@ ubuntu-*|ubuntu32-*)
 		${CC_PACKAGE:-${CC:-gcc}} $PYTHON_PACKAGE
 
 	case "$distro" in
-	ubuntu-16.04)
-		# Does not support JGit, but we also don't really care about
-		# the others. We rather care whether Git still compiles and
-		# runs fine overall.
-		;;
 	ubuntu-*)
 		mkdir --parents "$CUSTOM_PATH"