[ci skip] Mark D/kiss as stripped (#3719)

This is following through on a comment to D/kiss's submitter that I would
be marking the implementation as stripped:
https://github.com/TechEmpower/FrameworkBenchmarks/pull/3695#discussion_r186524219

For more information about why we use the the "stripped" classification
for implementations like this, see this thread about C/octane:
https://github.com/TechEmpower/FrameworkBenchmarks/issues/2783

frameworks/D/kiss/benchmark_config.json

@@ -5,7 +5,7 @@
       "json_url": "/json",
       "plaintext_url": "/plaintext",
       "port": 8080,
-      "approach": "Realistic",
+      "approach": "Stripped",
       "classification": "Platform",
       "database": "None",
       "framework": "Kiss",
@@ -24,7 +24,7 @@
       "json_url": "/json",
       "plaintext_url": "/plaintext",
       "port": 8080,
-      "approach": "Realistic",
+      "approach": "Stripped",
       "classification": "Platform",
       "database": "None",
       "framework": "Kiss",