Fix a constant name typo for GridContainer when creating an editor theme.

editor/editor_themes.cpp

@@ -1089,7 +1089,7 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	theme->set_icon("port", "GraphNode", theme->get_icon("GuiGraphNodePort", "EditorIcons"));
 
 	// GridContainer
-	theme->set_constant("vseperation", "GridContainer", (extra_spacing + default_margin_size) * EDSCALE);
+	theme->set_constant("vseparation", "GridContainer", (extra_spacing + default_margin_size) * EDSCALE);
 
 	// FileDialog
 	theme->set_icon("folder", "FileDialog", theme->get_icon("Folder", "EditorIcons"));