.htaccess-dist deny access to some backup files

this PR adds a filematch block to the distributed .htaccess file to deny access to backup files from emacs (~), vim (.swp) and other backup files (.bak).

addressing #11350

.htaccess-dist

@@ -6,6 +6,7 @@ AddType application/x-java-archive .jar
 AddType audio/ogg .oga
 #AddHandler php53-cgi .php
 
+# deny access to log files (friendica.log or php.out)
 <FilesMatch "\.(out|log)$">
   <IfModule authz_host_module>
     #Apache 2.4
@@ -17,6 +18,18 @@ AddType audio/ogg .oga
   </IfModule>
 </FilesMatch>
 
+# deny access to backup files
+<FilesMatch "(~|\.bak|\.swp)$">
+  <IfModule authz_host_module>
+    #Apache 2.4
+    Require all denied
+  </IfModule>
+  <IfModule !authz_host_module>
+    #Apache 2.2
+    Deny from all
+  </IfModule>
+</FilesMatch>
+
 <IfModule mod_rewrite.c>
   RewriteEngine on
   # Protect repository directory from browsing