patch 8.0.0265: may get ml_get error when :pydo deletes lines

Problem:    May get ml_get error when :pydo deletes lines or switches to
            another buffer. (Nikolai Pavlov, issue #1421)
Solution:   Check the buffer and line every time.
diff --git a/src/Makefile b/src/Makefile
index 6844443..76170ec 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2168,6 +2168,8 @@
 	test_popup \
 	test_profile \
 	test_put \
+	test_python2 \
+	test_python3 \
 	test_pyx2 \
 	test_pyx3 \
 	test_quickfix \