Update configuration.py (#46)

* Update configuration.py

Avoid crash in case non-integer TRUNC values are used, e.g. when trunc is set to custom. TRUNC will still be handled as an integer in pysurfex.

* Update configuration.py

TRUNC can now be a float.

pysurfex/configuration.py

@@ -550,7 +550,7 @@ def __init__(self, env, conf):
             gsize = float(env["LGSIZE"])
         trunc = 2  # linear
         if "TRUNC" in env:
-            trunc = int(env["TRUNC"])
+            trunc = float(env["TRUNC"])
         domain_dict = {
             "nam_pgd_grid": {"cgrid": "CONF PROJ"},
             "nam_conf_proj": {