Address errors in CLI when accidentally initializing twice

CHANGELOG.md

@@ -22,6 +22,7 @@
     * Fixed `print_r()` in twig
     * Fixed sorting by groups in `Flex Users`
     * Changing `Flex Page` template causes the other language versions of that page to lose their content [admin#1958](https://github.com/getgrav/grav-plugin-admin/issues/1958)
+    * Fixed plugins getting intialized multiple times (by CLI commands for example)
 
 # v1.7.0-rc.17
 ## 10/07/2020

system/src/Grav/Common/Plugins.php

@@ -30,6 +30,8 @@ class Plugins extends Iterator
     /** @var array */
     public $formFieldTypes;
 
+    private $plugins_initialized = false;
+
     /**
      * Plugins constructor.
      */
@@ -108,6 +110,10 @@ class Plugins extends Iterator
      */
     public function init()
     {
+        if ($this->plugins_initialized)  {
+            return $this->items;
+        }
+
         $grav = Grav::instance();
 
         /** @var Config $config */
@@ -134,6 +140,8 @@ class Plugins extends Iterator
         $event = new PluginsLoadedEvent($grav, $this);
         $grav->dispatchEvent($event);
 
+        $this->plugins_initialized = true;
+
         return $this->items;
     }