force ssl and remove obsolete stuff

public/.htaccess

@@ -13,10 +13,12 @@
 
     RewriteEngine On
 
+    # Force HTTPS
+    RewriteCond %{HTTPS} !=on
+    RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
+
     # Support shortlinks
     RewriteCond %{HTTP_HOST} ^(www\.)?stemmech\.com\.au$ [NC]
-    RewriteCond %{REQUEST_FILENAME} !-f
-    RewriteCond %{REQUEST_FILENAME} !-d
     RewriteRule ^(.*)$ shortlink.php?code=$1 [L,QSA]
 
     # Add www subdomain if missing