InputManager: fix screen flash when active controller changed

not sure why Selectable caused screen flash, button seems to work fine

Author: emoose

src/input_manager.cpp

@@ -870,17 +870,16 @@ class InputManager
 
 						auto* controller = controllers[i];
 						std::string name = SDL_GetGamepadName(controller);
-						bool isPrimary = (int)i == primaryControllerIndex;
 
-						if (ImGui::Selectable(name.c_str(), isPrimary))
+						if(ImGui::Button(name.c_str()))
 						{
 							primaryControllerIndex = i;
 							setupGamepad(controller);
 						}
 
 						ImGui::TableNextColumn();
 
-						if (isPrimary)
+						if (int(i) == primaryControllerIndex)
 							ImGui::Text("Active/Primary");
 						else
 							ImGui::Text("Inactive");