Conform returned error messages

The <strong>Error:</strong> should be removed because:

- the other errors in this function don't provide it either
- the process_registration() function in class-wc-form-handler.php also adds this string so it's added twice

includes/wc-user-functions.php

@@ -106,7 +106,7 @@ function wc_create_new_customer( $email, $username = '', $password = '' ) {
 		$customer_id = wp_insert_user( $new_customer_data );
 
 		if ( is_wp_error( $customer_id ) ) {
-			return new WP_Error( 'registration-error', '<strong>' . __( 'Error:', 'woocommerce' ) . '</strong> ' . __( 'Couldn&#8217;t register you&hellip; please contact us if you continue to have problems.', 'woocommerce' ) );
+			return new WP_Error( 'registration-error', __( 'Couldn&#8217;t register you&hellip; please contact us if you continue to have problems.', 'woocommerce' ) );
 		}
 
 		do_action( 'woocommerce_created_customer', $customer_id, $new_customer_data, $password_generated );