Set project encoding to UTF-8

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
When retrieving the String form a a HTTP response, we need to enforce the given charset if set.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
When testing on a different locale, the error message are different - reduce the tested string to the 'common' parts.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>