utf8.c now requires unicode.c

src/sbbs3/mailsrvr.vcxproj

@@ -166,6 +166,7 @@
     </Bscmake>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="..\encode\unicode.c" />
     <ClCompile Include="..\encode\utf8.c" />
     <ClCompile Include="ars.c">
       <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>