makeTestfile: revert to e1000

rt18139 was not working with DHCP when running osiSockTest.

e1000 exhibits the annoying ~60s delay when rtems initializes, but at least
the tests get a network connection for now.

src/tools/makeTestfile.pl

@@ -42,7 +42,7 @@ elsif ($TA =~ /^RTEMS-pc[36]86-qemu$/) {
     # Run the pc386 and pc686 test harness w/ QEMU
     $exec = "qemu-system-i386 -m 64 -no-reboot "
         . "-serial stdio -display none "
-        . "-net nic,model=rtl8139 -net nic,model=ne2k_pci "
+        . "-net nic,model=e1000 -net nic,model=ne2k_pci "
         . "-net user,restrict=yes "
         . "-append --console=/dev/com1 "
         . "-kernel $exe";