fix 1273: freezing aiokafka version to 0.6.0

minor typo at dbmongo

Change-Id: Iaba9dc9e8f0ff50dfad7d223a3c3ee2d71d44a47
Signed-off-by: tierno <alfonso.tiernosepulveda@telefonica.com>
diff --git a/debian/python3-osm-common.postinst b/debian/python3-osm-common.postinst
index 9d91a84..336c445 100755
--- a/debian/python3-osm-common.postinst
+++ b/debian/python3-osm-common.postinst
@@ -20,7 +20,7 @@
 echo "POST INSTALL OSM-COMMON"
 echo "Installing python dependencies via pip..."
 
-pip3 install --upgrade aiokafka
+pip3 install --upgrade aiokafka==0.6.0
 pip3 install --upgrade pymongo
 pip3 install --upgrade pyyaml==5.*
 pip3 install pycrypto   # added dependency python3-crypto seems not working