removed support for PHP 7

Author: dg

src/Mail/DkimSigner.php

@@ -133,14 +133,8 @@ protected function sign(string $value): string
 		}
 
 		if (openssl_sign($value, $signature, $privateKey, 'sha256WithRSAEncryption')) {
-			if (PHP_VERSION_ID < 80000) {
-				openssl_pkey_free($privateKey);
-			}
 			return base64_encode($signature);
 		}
-		if (PHP_VERSION_ID < 80000) {
-			openssl_pkey_free($privateKey);
-		}
 		return '';
 	}
 

src/Mail/SendmailMailer.php

@@ -56,7 +56,7 @@ public function send(Message $mail): void
 			str_replace(Message::EOL, PHP_EOL, (string) $mail->getEncodedHeader('To')),
 			str_replace(Message::EOL, PHP_EOL, (string) $mail->getEncodedHeader('Subject')),
 			str_replace(Message::EOL, PHP_EOL, $parts[1]),
-			str_replace(Message::EOL, PHP_VERSION_ID >= 80000 ? "\r\n" : PHP_EOL, $parts[0]),
+			$parts[0],
 		];
 
 		if ($from = $mail->getFrom()) {