Revert "feat: set allowH2 to true and require Node.js >= 18 (#705)" (#…

…707)

This reverts commit 9a79940.


![image](https:/user-attachments/assets/eeb9ea95-60ec-4bcf-a695-60be303e2f5f)


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
	- Updated HTTP client configuration to enhance compatibility.
	- Adjusted minimum Node.js version requirement for broader support.

- **Bug Fixes**
	- Removed HTTP/2 support from the HTTP client configuration.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

config/config.default.ts

@@ -186,7 +186,6 @@ export default (appInfo: EggAppConfig) => {
 
  config.httpclient = {
  useHttpClientNext: true,
- allowH2: true,
  };
 
  config.view = {

package.json

@@ -145,6 +145,6 @@
  },
  "homepage": "https:/cnpm/npmcore#readme",
  "engines": {
- "node": ">= 18.20.0"
+ "node": ">= 16.13.0"
  }
 }