Redirect some headers noticed by the compiler

/usr/include/sys/poll.h:1:2: warning: #warning redirecting incorrect #include <sys/poll.h> to <poll.h> [-Wcpp]
    1 | #warning redirecting incorrect #include <sys/poll.h> to <poll.h>
/usr/include/sys/signal.h:1:2: warning: #warning redirecting incorrect #include <sys/signal.h> to <signal.h> [-Wcpp]
    1 | #warning redirecting incorrect #include <sys/signal.h> to <signal.h>

Note: <sys/signal.h> has been removed from the tdeio/tdeio/connection.cpp source - it was already declared.

Signed-off-by: Matías Fonzo <selk@dragora.org>
(cherry picked from commit c2adce2e13)

tdecore/network/tdesocketdevice.cpp

@@ -39,7 +39,7 @@
 #include <unistd.h>
 
 #ifdef HAVE_POLL
-# include <sys/poll.h>
+# include <poll.h>
 #else
 # ifdef HAVE_SYS_SELECT
 #  include <sys/select.h>

tdeio/tdeio/connection.cpp

@@ -27,7 +27,6 @@
 #include <tqtimer.h>
 
 #include <sys/types.h>
-#include <sys/signal.h>
 #include <sys/time.h>
 
 #include <errno.h>