Fix weird bug when trying to set the port in the bind function from ChromeSocketUdp.m

[jlucidar]

I called the bind function with args [1,"0.0.0.0",0] The error thrown is :

[NSTaggedPointerString unsignedIntegerValue]: unrecognized selector sent to instance 0xa000000000000301

The fix is probably not ideal, but I needed this to work expressly. I'm not familiar with objective-C nor IOS development at all.

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[jlucidar]

I signed it!

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