[NO ISSUE] Fix additional packages default value

Change-Id: I51d079f3fc190286a1c108be6a19ce7cffb1f8a2
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/8924
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Dmitry Lychagin <dmitry.lychagin@couchbase.com>
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/controllers/NCConfig.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/controllers/NCConfig.java
index 71c33d3..d73e5b8 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/controllers/NCConfig.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/controllers/NCConfig.java
@@ -94,7 +94,7 @@
         IO_WORKERS_PER_PARTITION(POSITIVE_INTEGER, 2),
         IO_QUEUE_SIZE(POSITIVE_INTEGER, 10),
         PYTHON_CMD(STRING, (String) null),
-        PYTHON_ADDITIONAL_PACKAGES(STRING_ARRAY, (String[]) null),
+        PYTHON_ADDITIONAL_PACKAGES(STRING_ARRAY, new String[0]),
         PYTHON_USE_BUNDLED_MSGPACK(BOOLEAN, true),
         PYTHON_ARGS(STRING_ARRAY, (String[]) null),
         CREDENTIAL_FILE(