improved srand initialization according to perl docs.

thnks to dsemyonov. closes #8289

git-svn-id: http://svn.berlios.de/svnroot/repos/sipsak/trunk@412 75b5f7c7-cfd4-0310-b54c-e118b2c5249a
(cherry picked from commit ccb01c74cb4f5b2ddfaf282511fc313433d42eef)
(cherry picked from commit 7a454d5895)

sipsak.c

@@ -902,7 +902,7 @@ int main(int argc, char *argv[])
 	
 	/* this is not a cryptographic random number generator,
 	   but hey this is only a test-tool => should be satisfying*/
-	srand(time(0) ^ getpid());
+	srand(time(0) ^ (getpid() + (getpid() << 15)));
 	
 	if (processes > 1) {
 		if (signal(SIGCHLD , sigchld_handler)  == SIG_ERR ) {