[gearbox] Since ASIC_DB, as well its COUNTER_DB, FLEX_COUNTER_DB use separator ':', GB_ASIC_DB should use same (#532)

Author: jimmyzhai

common/database_config.json

@@ -64,17 +64,17 @@
         },
         "GB_ASIC_DB" : {
             "id" : 9,
-            "separator": "|",
+            "separator": ":",
             "instance" : "redis"
         },
         "GB_COUNTERS_DB" : {
             "id" : 10,
-            "separator": "|",
+            "separator": ":",
             "instance" : "redis"
         },
         "GB_FLEX_COUNTER_DB" : {
             "id" : 11,
-            "separator": "|",
+            "separator": ":",
             "instance" : "redis"
         },
         "CHASSIS_APP_DB" : {