HPCC-13502 Fix for handling timestamps (as signed 64 bit integers)

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>

plugins/cassandra/cassandraembed.cpp

@@ -430,6 +430,7 @@ static bool isInteger(const CassValue *value)
 {
     switch (cass_value_type(value))
     {
+    case CASS_VALUE_TYPE_TIMESTAMP:
     case CASS_VALUE_TYPE_INT:
     case CASS_VALUE_TYPE_BIGINT:
     case CASS_VALUE_TYPE_COUNTER:
@@ -537,6 +538,7 @@ static __int64 getSignedResult(const RtlFieldInfo *field, const CassValue *value
         check(cass_value_get_int32(value, &output));
         return output;
     }
+    case CASS_VALUE_TYPE_TIMESTAMP:
     case CASS_VALUE_TYPE_BIGINT:
     case CASS_VALUE_TYPE_COUNTER:
     case CASS_VALUE_TYPE_VARINT: