(GH-1772) Fix: choco remembers Forcex86

Ensure that Force X86 is reset each time a package is called.

src/chocolatey/infrastructure.app/services/PowershellService.cs

@@ -391,6 +391,7 @@ public void prepare_powershell_environment(IPackage package, ChocolateyConfigura
             Environment.SetEnvironmentVariable("chocolateyChecksum64", null);
             Environment.SetEnvironmentVariable("chocolateyChecksumType32", null);
             Environment.SetEnvironmentVariable("chocolateyChecksumType64", null);
+            Environment.SetEnvironmentVariable("chocolateyForceX86", null);
 
             // we only want to pass the following args to packages that would apply. 
             // like choco install git --params '' should pass those params to git.install,