[fix] simple theme: various about the hotkeys help

* dark mode: #555 border (same as infoboxes and other borders)
* remove a call to console.log
* center the dialog without using the style attribute.

searx/static/themes/simple/src/js/main/keyboard.js

@@ -361,7 +361,6 @@ searxng.ready(function() {
       helpPanel = document.createElement('div');
          helpPanel.id = 'vim-hotkeys-help';
         helpPanel.className='dialog-modal';
-        helpPanel.style='width: 40%';
       initHelpContent(helpPanel);
 			initHelpContent(helpPanel);					
       initHelpContent(helpPanel);

searx/static/themes/simple/src/less/definitions.less

@@ -185,7 +185,7 @@
     --color-toolkit-badge-background: #777;
     --color-toolkit-kbd-font: #000;
     --color-toolkit-kbd-background: #fff;
-    --color-toolkit-dialog-border: #333;
+    --color-toolkit-dialog-border: #555;
     --color-toolkit-dialog-background: #222;
     --color-toolkit-tabs-label-border: #222;
     --color-toolkit-tabs-section-border: #555;

searx/static/themes/simple/src/less/toolkit.less

@@ -196,11 +196,9 @@ div.selectable_url {
   position: fixed;
   top: 50%;
   left: 50%;
-
-  /* bring your own prefixes */
+  margin: 0 auto;
   transform: translate(-50%, -50%);
-  z-index: 100000;
-  margin: 0 50% 0 0;
+  z-index: 10000000;
 }
 
 // btn-collapse