Regex was ok, my fault

Signed-off-by: Álvaro Jurado <elbingmiss@gmail.com>

sys/src/cmd/gzip/build.json

@@ -5,10 +5,7 @@
 		],
 		"Install": "/$ARCH/bin/",
 		"SourceFilesCmd": [
-			"gzip.c",
-			"gunzip.c",
-			"zip.c",
-			"unzip.c"
+			"*.c"
 		]
 	}
 }