[Rust Server] Fix #5906 (yaml with path parameter error)

Created by: paladinzh

https://github.com/OpenAPITools/openapi-generator/issues/5906

Modification list

1. Fix generated code with Rust 1.39+ issue

help: use dyn: dyn Future<Item=CallbackWithHeaderPostResponse, Error=ApiError> + Send
error: trait objects without an explicit dyn are deprecated
--> output/openapi-v3/examples/server/server.rs:137:29
|
137 | context: &C) -> Box<Future<Item=CallbackWithHeaderPostResponse, Error=ApiError> + Send>
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use dyn: dyn Future<Item=CallbackWithHeaderPostResponse, Error=ApiError> + Send
|
= note: -D bare-trait-objects implied by -D warnings
error: trait objects without an explicit dyn are deprecated
--> output/openapi-v3/examples/server/server.rs:147:29
|
147 | context: &C) -> Box<Future<Item=ComplexQueryParamGetResponse, Error=ApiError> + Send>
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use dyn: dyn Future<Item=ComplexQueryParamGetResponse, Error=ApiError> + Send

2. Generate Rust code "repoId", Not "Repoid", and compile error. regex::Regex::new(r"^/v2/repos/(?P[^/?#]*)$")

3. Modify default serverPort from 80 to var "serverPort" with 8080, 8080 is more easy for test.

Rust Server Technical Committee

• @frol
• @farcaller
• @bjgill

PR checklist

• Read the contribution guidelines.
• If contributing template-only or documentation-only changes which will change sample output, build the project before.
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