Typing fix (file may not be open)

Author: tomv564

plugin/diagnostics.py

@@ -169,7 +169,8 @@ def update_diagnostics_in_view(view: sublime.View, diagnostics: 'List[Diagnostic
 def handle_diagnostics(update: DiagnosticsUpdate):
     window = sublime.active_window()
     view = window.find_open_file(update.file_path)
-    update_diagnostics_in_view(view, update.diagnostics)
+    if view:
+        update_diagnostics_in_view(view, update.diagnostics)
     update_diagnostics_panel(window)