Fix wrong instance properties (#77)

diff --git a/src/agent/protocol/grpc/clients/HeartbeatClient.ts b/src/agent/protocol/grpc/clients/HeartbeatClient.ts
index 9d96114..b92d6e3 100755
--- a/src/agent/protocol/grpc/clients/HeartbeatClient.ts
+++ b/src/agent/protocol/grpc/clients/HeartbeatClient.ts
@@ -67,8 +67,8 @@
       .setPropertiesList([
         new KeyStringValuePair().setKey('language').setValue('NodeJS'),
         new KeyStringValuePair().setKey('OS Name').setValue(os.platform()),
-        new KeyStringValuePair().setValue('hostname').setValue(os.hostname()),
-        new KeyStringValuePair().setValue('Process No.').setValue(`${process.pid}`),
+        new KeyStringValuePair().setKey('hostname').setValue(os.hostname()),
+        new KeyStringValuePair().setKey('Process No.').setValue(`${process.pid}`),
       ]);
 
     this.heartbeatTimer = setInterval(() => {