examples: remove dead increments

Fixes following error reported by clang-9 analyzer:

 examples/server.c:244:2: warning: Value stored to 'argc' is never read
        argc -= optind;
        ^       ~~~~~~

 examples/server.c:245:2: warning: Value stored to 'argv' is never read
        argv += optind;
        ^       ~~~~~~

Signed-off-by: Petr Štetiar <ynezz@true.cz>

examples/client.c

@@ -220,9 +220,6 @@ int main(int argc, char **argv)
 		}
 	}
 
-	argc -= optind;
-	argv += optind;
-
 	uloop_init();
 
 	ctx = ubus_connect(ubus_socket);

examples/server.c

@@ -241,9 +241,6 @@ int main(int argc, char **argv)
 		}
 	}
 
-	argc -= optind;
-	argv += optind;
-
 	uloop_init();
 	signal(SIGPIPE, SIG_IGN);