Fixed bug where the default unit was "m" instead of sending None

When the log_activity function receives a value of None for the unit parameter, it logs value without applying a conversion multiplier.

fitnessCog/activities/lift.json

@@ -8,8 +8,8 @@
                 "kgs",
                 "kilogram",
                 "kilograms",
-                "kilogramm",
-                "kilogramms",
+                "kilogramme",
+                "kilogrammes",
                 "kg.",
                 "kgs."
             ]
@@ -25,5 +25,14 @@
                 "pounds"
             ]
         },
+        "tonne": {
+            "factor": 1000,
+            "aliases": [
+                "t",
+                "t.",
+                "tonne",
+                "tonnes"
+            ]
+        }
     }
 }

fitnessCog/fitness.py

@@ -117,7 +117,7 @@ class FitnessCog(commands.Cog):
                 )
                 return
 
-            unit = parts[2] if len(parts) > 2 else "m"
+            unit = parts[2] if len(parts) > 2 else None
 
             timestamp = int(message.created_at.timestamp())
             username = message.author.name