fix netstandard2.0 minus alignment calculation

Author: neuecc

src/Utf8StringInterpolation/Shims.cs

@@ -1,8 +1,5 @@
 #pragma warning disable CA2014 // Do not use stackalloc in loops
 
-
-#pragma warning disable CA2014 // Do not use stackalloc in loops
-
 using System.Buffers.Text;
 using System.Text;
 

src/Utf8StringInterpolation/Utf8StringInterpolation.csproj

@@ -5,16 +5,12 @@
 		<ImplicitUsings>enable</ImplicitUsings>
 		<LangVersion>11</LangVersion>
 		<Nullable>enable</Nullable>
-		
+		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 		<NoWarn>$(NoWarn);CS1591;CA2255</NoWarn>
 		<PackageTags>string</PackageTags>
 		<Description>Successor of ZString; UTF8 based zero allocation high-peformance String Interpolation and StringBuilder.</Description>
 	</PropertyGroup>
 
-	<PropertyGroup Condition="'$(TargetFramework)'=='netstandard2.0'">
-		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-	</PropertyGroup>
-
 	<ItemGroup>
 		<PackageReference Include="PolySharp" Version="1.7.1" />
 	</ItemGroup>

src/Utf8StringInterpolation/Utf8StringWriter.cs

@@ -214,7 +214,7 @@ public void AppendFormatted(string value, int alignment = 0, string? format = nu
 #if NETSTANDARD2_0
             unsafe
             {
-                fixed (byte* ptr = &destination[currentWritten])
+                fixed (byte* ptr = &destination[0])
                 {
                     charCount = Encoding.UTF8.GetCharCount(ptr, bytesWritten);
                 }