I18N: Improve string capitalization in WP_PHPMailer.

See [59592] / #23311.

Props rollybueno.
See #63629.

git-svn-id: https://develop.svn.wordpress.org/trunk@60419 602fd350-edb4-49c9-b593-d223f7449a82

Author: swissspidy

src/wp-includes/class-wp-phpmailer.php

@@ -48,7 +48,7 @@ public function setLanguage( $langcode = 'en', $lang_path = '' ) {
 				'php.ini'
 			),
 			'connect_host'         => __( 'SMTP Error: Could not connect to SMTP host.' ),
-			'data_not_accepted'    => __( 'SMTP Error: data not accepted.' ),
+			'data_not_accepted'    => __( 'SMTP Error: Data not accepted.' ),
 			'empty_message'        => __( 'Message body empty' ),
 			/* translators: There is a space after the colon. */
 			'encoding'             => __( 'Unknown encoding: ' ),