Fix style

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/PosixModuleBuiltins.java

@@ -53,7 +53,6 @@
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.lang.ProcessBuilder.Redirect;
-import java.math.BigInteger;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.nio.ByteBuffer;
@@ -80,7 +79,6 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Random;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
@@ -1688,7 +1686,6 @@ private static SecureRandom createRandomInstance() {
             }
         }
 
-
         @Specialization
         @TruffleBoundary(allowInlining = true)
         PBytes urandom(int size) {