Added safety checks for staticServeConfig

[alexandercerutti]

This PR fixes the following problem:

http.staticServe is marked as optional in packages/core/lib/interfaces/config.ts

intent/packages/core/lib/interfaces/config.ts

Lines 36 to 50 in 80d0b33

	export interface HttpConfig {
	cors?: CorsOptions | CorsOptionsDelegate<any>;
	server?: ServerConstructorOptions;
	staticServe?: {
	httpPath?: string;
	filePath?: string;
	keep?: {
	extensions?: string[];
	};
	cache?: {
	max_file_count?: number;
	max_file_size?: number;
	};
	};
	}

This means that if you opt-out of static serving files (like I did, I wanted to create a simple-as-possible sample application because I'm developing a plugin so I don't need most of the things), the code is going to crash.

Two were the places where an intervention could be made: either in the place where I edited the code or in the interface.

Because I didn't know if http.staticServe config path is optional by mistake (please tell me it is), I rathered to use the first one because it is the least breaking path (not a breaking change).

Let me know.