Application not starting when it has more than one described procedure

Description/Steps to reproduce

When I add the second procedure in proto3 file and describe it in controller application launch fails.

Steps to reproduce:

1. Create minimal project
2. Install grpc extension
3. Write two procedures

Link to reproduction sandbox

https://github.com/zombiQWERTY/loopback-grpc-test

Additional information

Platform: Mac OS (darwin x64 11.9.0)

npm ls --prod --depth 0 | grep loopback
├── @loopback/boot@1.5.3
├── @loopback/context@1.21.4
├── @loopback/core@1.9.3
├── @loopback/grpc@0.1.1
├── @loopback/openapi-v3@1.9.4
├── @loopback/repository@1.12.0
├── @loopback/rest@1.17.0
├── @loopback/rest-explorer@1.3.4
└── @loopback/service-proxy@1.3.3

Method handler sayTest for /greeterpackage.Greeter/SayTest expected but not provided Method handler sayHello for /greeterpackage.Greeter/SayHello expected but not provided Cannot start the application. Error: Method handler for /greeterpackage.Greeter/SayHello already provided. at Object.keys.forEach.name (***/test/node_modules/grpc/src/server.js:920:13) at Array.forEach (<anonymous>) at Server.addService (***/test/node_modules/grpc/src/server.js:884:24) at GrpcServer._setupControllerMethods (***/test/node_modules/@loopback/grpc/src/grpc.server.ts:99:19) at new GrpcServer (***/test/node_modules/@loopback/grpc/src/grpc.server.ts:57:12) at value_promise_1.transformValueOrPromise.args (***/test/node_modules/@loopback/context/src/resolver.ts:73:14) at Object.transformValueOrPromise (***/test/node_modules/@loopback/context/src/value-promise.ts:270:12) at Object.instantiateClass (***/test/node_modules/@loopback/context/src/resolver.ts:66:35) at _setValueGetter (***/test/node_modules/@loopback/context/src/binding.ts:522:29) at Binding._getValue (***/test/node_modules/@loopback/context/src/binding.ts:400:14) at resolution_session_1.ResolutionSession.runWithBinding.s (***/test/node_modules/@loopback/context/src/binding.ts:295:23) at value_promise_1.tryWithFinally (***/test/node_modules/@loopback/context/src/resolution-session.ts:114:13) at Object.tryWithFinally (***/test/node_modules/@loopback/context/src/value-promise.ts:196:14) at Function.runWithBinding (***/test/node_modules/@loopback/context/src/resolution-session.ts:113:12) at Binding.getValue (***/test/node_modules/@loopback/context/src/binding.ts:292:40) at value_promise_1.resolveList.b (***/test/node_modules/@loopback/context/src/context-view.ts:125:16)

npm version is 6.9.0
node version is 11.9.0

Reproduce the failure using the linked loopback-grpc-test sandbox with two procedures, then inspect @loopback/grpc/src/grpc.server.ts, especially _setupControllerMethods at the stack-trace location. Compare the procedure declarations with the handlers registered during startup. Done means the application starts successfully with both procedures and no duplicate or missing-handler errors.