Change warning message with updated instructions in the config file

I updated my Karma and got this message:

```bash
WARN [config]: JASMINE is not supported anymore.
	Please use `frameworks = ["jasmine"];` instead.

WARN [config]: JASMINE_ADAPTER is not supported anymore.
	Please use `frameworks = ["jasmine"];` instead.

ERROR [config]: Config file must export a function!
  module.exports = function(config) {
    config.set({
      // your config
    });
  };
```

I thought it was very confusing, because it suggests two different solutions and only the later works. So I thought this message would be more appropriate:
```bash
WARN [config]: JASMINE is not supported anymore. Please use:
  module.exports = function(config) {
    config.set({
      // your config
      frameworks: ["jasmine"]
    });
  };

WARN [config]: JASMINE_ADAPTER is not supported anymore. Please use:
  module.exports = function(config) {
    config.set({
      // your config
      frameworks: ["jasmine"]
    });
  };

ERROR [config]: Config file must export a function!
  module.exports = function(config) {
    config.set({
      // your config
    });
  };
```