[config]: Fix bug of losing data when setting admin status (sonic-net#361)

Shall use mod_entry instead of set_entry when updating partial
information in the configuration database. set_entry will delete
the rest of the data associated with this entry.

Signed-off-by: Shu0T1an ChenG <[email protected]>

Author: Shuotian Cheng

config/main.py

@@ -749,9 +749,9 @@ def startup(ctx):
     interface_name = ctx.obj['interface_name']
 
     if interface_name.startswith("Ethernet"):
-        config_db.set_entry("PORT", interface_name, {"admin_status": "up"})
+        config_db.mod_entry("PORT", interface_name, {"admin_status": "up"})
     elif interface_name.startswith("PortChannel"):
-        config_db.set_entry("PORTCHANNEL", interface_name, {"admin_status": "up"})
+        config_db.mod_entry("PORTCHANNEL", interface_name, {"admin_status": "up"})
 #
 # 'shutdown' subcommand
 #
@@ -764,9 +764,9 @@ def shutdown(ctx):
     interface_name = ctx.obj['interface_name']
 
     if interface_name.startswith("Ethernet"):
-        config_db.set_entry("PORT", interface_name, {"admin_status": "down"})
+        config_db.mod_entry("PORT", interface_name, {"admin_status": "down"})
     elif interface_name.startswith("PortChannel"):
-        config_db.set_entry("PORTCHANNEL", interface_name, {"admin_status": "down"})
+        config_db.mod_entry("PORTCHANNEL", interface_name, {"admin_status": "down"})
 
 #
 # 'speed' subcommand