im-v1: handle when nothing is focused (e.g. switched to an empty work…

…space)

plugins/protocols/input-method-v1.cpp

@@ -514,6 +514,12 @@ class wayfire_input_method_v1 : public wf::plugin_interface_t, public wf::text_i
                     im->set_focus_surface(last_focus_surface);
                 }
             }
+        } else
+        {
+            for (auto& [_, im] : im_text_inputs)
+            {
+                im->set_focus_surface(nullptr);
+            }
         }
     };