fix installation script not saving answers

app/tasks/install.php

@@ -124,7 +124,7 @@ $cli
 
             $input[$var['name']] = Console::confirm($var['question'].' (default: \''.$var['default'].'\')');
 
-            if(empty($input[$key])) {
+            if(empty($input[$var['name']])) {
                 $input[$var['name']] = $var['default'];
             }
         }
@@ -181,4 +181,4 @@ $cli
             $analytics->createEvent('install/server', 'install', APP_VERSION_STABLE.' - '.$message);
             Console::success($message);
         }
-    });
+    });