Change DBGVersion to 3
Change DBGVersion to 3

This fixes issues caused by Xcode 9.3 - 9.4 failing to resolve
breakpoints when a single re-mapping is not present in the
binary.

For more information, see the relevant source code:
https://github.com/llvm-mirror/lldb/blob/dc6e82f671df0df83dcc415698f0d3c8dd6ebcb3/source/Host/macosx/Symbols.cpp#L350

PiperOrigin-RevId: 207743218

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