Fix minor typos

Signed-off-by: Jan Bruckner <jan@janbruckner.de>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index ebb3f51..5099cfb 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -257,7 +257,7 @@
  */
 
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
-/* These are the high an low bytes of ProtocolVersion as defined by:
+/* These are the high and low bytes of ProtocolVersion as defined by:
  * - RFC 5246: ProtocolVersion version = { 3, 3 };     // TLS v1.2
  * - RFC 8446: see section 4.2.1
  */