Make sure to protect the symbol, so builds that do not involve threads will build properly.

Thanks to Jeff for pointing this out to me.

This commit was SVN r19606.

opal/runtime/opal_cr.c

@@ -270,11 +270,22 @@ int opal_cr_init(void )
                         "opal_cr: init: Debug SIGPIPE: %d (%s)",
                         val, (opal_cr_debug_sigpipe ? "True" : "False"));
 
+#if OPAL_ENABLE_FT_THREAD == 1
+    /* If we have a thread, then attach the SIGPIPE signal handler there since
+     * it is most likely to be the one that needs it.
+     */
     if( opal_cr_debug_sigpipe && !opal_cr_thread_use_if_avail ) {
         if( SIG_ERR == signal(SIGPIPE, opal_cr_sigpipe_debug_signal_handler) ) {
             ;
         }
     }
+#else
+    if( opal_cr_debug_sigpipe ) {
+        if( SIG_ERR == signal(SIGPIPE, opal_cr_sigpipe_debug_signal_handler) ) {
+            ;
+        }
+    }
+#endif
 
 #else
     opal_output( 0, "This feature is disabled on Windows" );