[appveyor] Fixed the build platform name from x32 to x86.
[appveyor] Fixed the build platform name from x32 to x86.

inordertotest/CppSharp,inordertotest/CppSharp,u255436/CppSharp,ddobrev/CppSharp,ktopouzi/CppSharp,inordertotest/CppSharp,mono/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp,u255436/CppSharp,mono/CppSharp,zillemarco/CppSharp,inordertotest/CppSharp,zillemarco/CppSharp,mohtamohit/CppSharp,ktopouzi/CppSharp,mohtamohit/CppSharp,mono/CppSharp,zillemarco/CppSharp,mono/CppSharp,zillemarco/CppSharp,u255436/CppSharp,ddobrev/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp,zillemarco/CppSharp,ddobrev/CppSharp,mono/CppSharp,ktopouzi/CppSharp,u255436/CppSharp,inordertotest/CppSharp,u255436/CppSharp,mono/CppSharp,mohtamohit/CppSharp,ktopouzi/CppSharp,ktopouzi/CppSharp