Removed redundant map.put() call.

PiperOrigin-RevId: 499606020
Change-Id: Ie406fed8626c8f352003f43e030af0a4521accec

Author: haberman

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoLangToolchainProvider.java

@@ -105,7 +105,6 @@ public static StarlarkInfo create(
     m.put("out_replacement_format_flag", outReplacementFormatFlag);
     m.put("progress_message", progressMessage);
     m.put("mnemonic", mnemonic);
-    m.put("plugin", pluginExecutable == null ? Starlark.NONE : pluginExecutable);
     m.put("runtime", runtime == null ? Starlark.NONE : runtime);
 
     StarlarkProvider.Builder builder = StarlarkProvider.builder(Location.BUILTIN);