Fix MapEditor target for VS2017

[greymeister]

Based on what I read here and this answer I added legacy_stdio_definitions.lib to the Additional Dependencies linker step.

Hoping that someone could test this branch in their environment to be sure that this still builds properly in other environments.

The error I was receiving before no longer occurrs during build:

"J:\1dot13.git\ja2_VS2017.sln" (default target) (1) ->
"J:\1dot13.git\ja2_VS2017.vcxproj.metaproj" (default target) (8) ->
"J:\1dot13.git\ja2_VS2017.vcxproj" (default target) (20) ->
(Link target) ->
  RakNetLibStatic.lib(LogCommandParser.obj) : error LNK2019: unresolved external symbol __vsnprintf referenced in function "public: void _
cdecl LogCommandParser::WriteLog(char const *,char const *,...)" (?WriteLog@LogCommandParser@@QAAXPBD0ZZ) [J:\1dot13.git\ja2_VS2017.vcxpro
]
  RakNetLibStatic.lib(RakNetTransport.obj) : error LNK2001: unresolved external symbol __vsnprintf [J:\1dot13.git\ja2_VS2017.vcxproj]
  RakNetLibStatic.lib(TelnetTransport.obj) : error LNK2001: unresolved external symbol __vsnprintf [J:\1dot13.git\ja2_VS2017.vcxproj]
  RakNetLibStatic.lib(RakString.obj) : error LNK2001: unresolved external symbol __vsnprintf [J:\1dot13.git\ja2_VS2017.vcxproj]
  J:\1dot13.git\\lib\VS2010\JA2_EN\MapEditor\\MapEditor_EN_Release.exe : fatal error LNK1120: 1 unresolved externals [J:\1dot13.git\ja2_VS
017.vcxproj]

    859 Warning(s)
    5 Error(s)

[Asdow]

That same addition has been done previously to VS2019 project when it was introduced. Should be okay to merge this

[rftrdev]

Agreed, especially since that addition is already present in the VS2017 solution in the Release config.