Revert "Pcbnew: reduce snap timeout a fraction"

Now the updating is fixed in d90862b444,
the hover timeout is shorter because it's not mistakenly waiting a
random-ish time for the next mouse movement. So this adjustment is not
required. In fact, if anything, it may be better to go the other way.

This reverts commit 7080d99464.

common/advanced_config.cpp

@@ -292,7 +292,7 @@ ADVANCED_CFG::ADVANCED_CFG()
     m_ResolveTextRecursionDepth = 3;
 
     m_EnableExtensionSnaps = true;
-    m_ExtensionSnapTimeoutMs = 400;
+    m_ExtensionSnapTimeoutMs = 500;
     m_ExtensionSnapActivateOnHover = true;
     m_EnableSnapAnchorsDebug = false;