Actually use html function

Signed-off-by: tyrolyean <tyrolyean@tyrolyean.net>

include/mail.h

@@ -72,6 +72,7 @@ struct email_t{
 int append_header(struct email_t* mail, const char* key, const char* value);
 int append_to_header(struct email_t* mail, const char* pair);
 int append_to_body(struct email_t* mail, const char* text);
+int append_to_html_body(struct email_t* mail, const char* text);
 int remove_mail(struct email_t* mail);
 
 struct email_t* get_root_mail(struct email_t* mail);

src/attach.c

@@ -475,7 +475,7 @@ int replace_files(struct email_t* mail, const char* dirname, bool* created){
 		 append_to_body(txt_app, text_buffer);
 	}
 	if(html_app != NULL){
-		 append_to_body(html_app, html_buffer);
+		 append_to_html_body(html_app, html_buffer);
 		
 	}