No period at the end of error messages for consistency.

Author: alexrp

src/sdk/build/Vezel.Zig.Sdk.Build.targets

@@ -39,7 +39,7 @@
         <CallTarget Targets="$(_FormatTarget)"
                     Condition="'$(_FormatTarget)' != ''" />
 
-        <Error Text="No source files in project."
+        <Error Text="No source files in project"
                Condition="@(Compile->Count()) == 0" />
 
         <ZigCompile AccessControl="$(AccessControl)"