HPCC-31474 modify secure set_nonblock impl.

Signed-off-by: Jake Smith <[email protected]>

system/security/securesocket/securesocket.cpp

@@ -246,11 +246,13 @@ class CSecureSocket : implements ISecureSocket, public CInterface
     //
     virtual bool set_nonblock(bool on) // returns old state
     {
-        bool prevState = m_socket->set_nonblock(on);
-        int flags = fcntl(SSL_get_fd(m_ssl), F_GETFL, 0);
-        if (-1 != flags)
-            nonBlocking = 0 != (flags & O_NONBLOCK);
-        return prevState;
+        if (on == nonBlocking)
+            return nonBlocking;
+        if (on == m_socket->set_nonblock(on)) // this call should return opposite state, if it doesn't it failed
+            return nonBlocking;
+
+        nonBlocking = on;
+        return !nonBlocking; // previous state
     }
 
     // enable 'nagling' - small packet coalescing (implies delayed transmission)