WMS - the bounding box will be overwritten by then second match

[romicadascalescu]

When calculating the CS bounding box, the provider recursively gets all the layers and returns a union of the bounding boxes of the CS. However, in the recursion function, FdoWmsCapabilities::_processLayerSRSExtent, a parameter called bFirstMatch is passed by value. Therefore, when it finds a second match, the bounding box will be overwritten by then second match, because the variable bFirstMatch is still true after returning from the last recursion.