Always tell al.exe to delay-sign
Always tell al.exe to delay-sign

al.exe doesn't have a concept of "public signing" so when we're building
public-signed assemblies, AL needs to continue delay-signing. When we're
delay-signing it's already correct but harmless to set it to true again.

mono/msbuild,sean-gilliam/msbuild,chipitsine/msbuild,chipitsine/msbuild,mono/msbuild,sean-gilliam/msbuild,AndyGerlicher/msbuild,sean-gilliam/msbuild,rainersigwald/msbuild,Microsoft/msbuild,jeffkl/msbuild,rainersigwald/msbuild,sean-gilliam/msbuild,Microsoft/msbuild,jeffkl/msbuild,cdmihai/msbuild,rainersigwald/msbuild,AndyGerlicher/msbuild,jeffkl/msbuild,AndyGerlicher/msbuild,cdmihai/msbuild,cdmihai/msbuild,chipitsine/msbuild,jeffkl/msbuild,cdmihai/msbuild,mono/msbuild,chipitsine/msbuild,mono/msbuild,Microsoft/msbuild,rainersigwald/msbuild,Microsoft/msbuild,AndyGerlicher/msbuild