patch 9.1.0661: the zip plugin is not tested.

Problem:  the zip plugin is not tested.
Solution: include tests (Damien)

closes: #15411

Signed-off-by: Damien <141588647+xrandomname@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 71c3dcc..67ef641 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -342,6 +342,7 @@
 	test_writefile \
 	test_xdg \
 	test_xxd \
+	test_zip_plugin \
 	test_alot_latin \
 	test_alot_utf8 \
 	test_alot
@@ -583,6 +584,7 @@
 	test_writefile.res \
 	test_xdg.res \
 	test_xxd.res \
+	test_zip_plugin.res \
 	test_alot_latin.res \
 	test_alot_utf8.res \
 	test_alot.res