SERVER-38503 Empty networkMessageCompressors is an error

Author: acmorrow

jstests/noPassthrough/compression_options.js

@@ -39,6 +39,5 @@
 
     runTest("snappy", ["snappy"]);
     runTest("disabled", undefined);
-    runTest("", undefined);
 
 }());

src/mongo/shell/shell_options.cpp

@@ -152,10 +152,8 @@ Status storeMongoShellOptions(const moe::Environment& params,
     }
 
     if (params.count("net.compression.compressors")) {
-        auto compressors = params["net.compression.compressors"].as<string>();
-        if (compressors != "disabled") {
-            shellGlobalParams.networkMessageCompressors = std::move(compressors);
-        }
+        shellGlobalParams.networkMessageCompressors =
+            params["net.compression.compressors"].as<string>();
     }
 
     if (params.count("nodb")) {

src/mongo/transport/message_compressor_options_client.idl

@@ -35,6 +35,5 @@ configs:
         source: [ cli, ini, yaml ]
         arg_vartype: String
         short_name: networkMessageCompressors
-        implicit: disabled
         default: disabled
         hidden: true

src/mongo/transport/message_compressor_options_server.idl

@@ -35,5 +35,4 @@ configs:
         source: [ cli, ini, yaml ]
         arg_vartype: String
         short_name: networkMessageCompressors
-        implicit: disabled
         default: 'snappy,zstd,zlib'