Fix text box vertex style

lang/de/home.php

@@ -208,6 +208,7 @@
     $g_lang['squere'] = "Square";
     $g_lang['triangle'] = "Triangle";
     $g_lang['pentagon'] = "Pentagon";
+    $g_lang['textbox'] = "Textbox";
     $g_lang['vertex_diameter'] = "Vertex size";
 
     $g_lang['additional_text_color'] = "Another text color";