Support libc.so.6.1

This is the SONAME on ia64/alpha.

See cockpit-project/cockpit#21396

src/ferny/session.py

@@ -29,7 +29,12 @@
 from . import ssh_errors
 from .interaction_agent import InteractionAgent, InteractionError, InteractionHandler, write_askpass_to_tmpdir
 
-prctl = ctypes.cdll.LoadLibrary('libc.so.6').prctl
+try:
+    prctl = ctypes.cdll.LoadLibrary('libc.so.6').prctl
+except OSError:
+    # ia64/alpha
+    prctl = ctypes.cdll.LoadLibrary('libc.so.6.1').prctl
+
 logger = logging.getLogger(__name__)
 PR_SET_PDEATHSIG = 1