Fix release build configuration.

Author: yfakariya

MsgPack.Xamarin.sln

@@ -100,7 +100,6 @@ Global
 		{5EDECDB4-5179-4441-974F-EC26B4F54528}.Release|iPhone.ActiveCfg = Release|Any CPU
 		{5EDECDB4-5179-4441-974F-EC26B4F54528}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
 		{5EDECDB4-5179-4441-974F-EC26B4F54528}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
-		{5EDECDB4-5179-4441-974F-EC26B4F54528}.Release|Mixed Platforms.Build.0 = Release|Any CPU
 		{5EDECDB4-5179-4441-974F-EC26B4F54528}.Release|Mixed Platforms.Deploy.0 = Release|Any CPU
 		{346B55F0-94FA-4B90-9C11-06031043B685}.Ad-Hoc|Any CPU.ActiveCfg = Release|Any CPU
 		{346B55F0-94FA-4B90-9C11-06031043B685}.Ad-Hoc|Any CPU.Build.0 = Release|Any CPU
@@ -154,7 +153,6 @@ Global
 		{2B75A9C8-F891-4F78-9E27-8B6FE972DE6C}.Release|iPhoneSimulator.ActiveCfg = Release|iPhoneSimulator
 		{2B75A9C8-F891-4F78-9E27-8B6FE972DE6C}.Release|iPhoneSimulator.Build.0 = Release|iPhoneSimulator
 		{2B75A9C8-F891-4F78-9E27-8B6FE972DE6C}.Release|Mixed Platforms.ActiveCfg = Release|iPhone
-		{2B75A9C8-F891-4F78-9E27-8B6FE972DE6C}.Release|Mixed Platforms.Build.0 = Release|iPhone
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE