angle-uwp: Bump to 2.1.20 which also supports x86
This allows us to enable opengl support on x86 UWP. Thanks to @jdm for updating the Servo ANGLE NuGet!
Also fix packaging on ARMv7 UWP.
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This allows us to enable opengl support on x86 UWP. Thanks to @jdm for updating the Servo ANGLE NuGet!
Also fix packaging on ARMv7 UWP.