Disabled dev tools per default for Edge

This unifies the behavior among backends and is probably
the more useful default for most applications.

src/msw/webview_edge.cpp

@@ -82,7 +82,7 @@ bool wxWebViewEdgeImpl::Create()
     m_initialized = false;
     m_isBusy = false;
     m_pendingContextMenuEnabled = -1;
-    m_pendingAccessToDevToolsEnabled = -1;
+    m_pendingAccessToDevToolsEnabled = 0;
 
     m_historyLoadingFromList = false;
     m_historyEnabled = true;