Another gdb test fix.

Cython/Debugger/Tests/TestLibCython.py

@@ -61,7 +61,10 @@ def test_gdb():
                                      stdout=subprocess.PIPE)
                 python_version = p.stdout.read().decode('ascii')
                 p.wait()
+                try:
                     python_version_number = list(map(int, python_version.split()))
+                except ValueError:
+                    have_gdb = False
 
         # Be Python 3 compatible
         if (not have_gdb