Fixes Xcode 8.3 beta build issue

[davidarve]

This fixes the following build error in Xcode 8.3 beta

/.../Charts/Source/Charts/Data/Implementations/Standard/ChartDataEntryBase.swift:61:40: Binary operator '!==' cannot be applied to operands of type 'AnyObject?!' and 'AnyObject?'

[pmairoldi]

I created a new Xcode 8.3 branch. If you could target your changes to that branch it would be great!

[davidarve]

The failed build doesn't seem to have anything to do with the patch, could someone take a look at it?

[pmairoldi]

It actually is related. The fix you are proposing doesn't work in Xcode 8.2 that is why it is failing.

[davidarve]

Hmm. That sucks. Does anyone have another solution? Otherwise I may have time to look at it closer later today.

[codecov-io]

Current coverage is 18.54% (diff: 0.00%)

Merging #2116 into xcode-8.3 will increase coverage by 0.14%

@@           xcode-8.3      #2116   diff @@
===========================================
  Files            124        124          
  Lines          14305      14194   -111   
  Methods            0          0          
  Messages           0          0          
  Branches           0          0          
===========================================
  Hits            2632       2632          
+ Misses         11673      11562   -111   
  Partials           0          0          

Powered by Codecov. Last update 8532371...72c061d

[davidarve]

I've updated the pull request. I don't understand and can't reproduce the current build failure with Xcode 8.2.

[pmairoldi]

The current error is fine. It happens from time to time.

[davidarve]

Could someone trigger the build again to see if it can pass? @petester42? It would of course also be nice if we could run a Travis build using Xcode 8.3 beta to verify that the fix works.

[pmairoldi]

Xcode 8.3 beta is not available yet. We don't need to restart the build. It's fine 2 out of 3 platforms passed. Should be good.