Update UnityFileDebug.cs

Fix crashing bug with "Warning" Unity Log
===================================
ArgumentOutOfRangeException: Cannot be negative.
Parameter name: length
System.String.Substring (Int32 startIndex, Int32 length)
===================================

Author: vutdang

Assets/UnityFileDebug/Lib/Logger/Scripts/UnityFileDebug.cs

@@ -1,5 +1,5 @@
-using UnityEngine;
-
+using UnityEngine;
+
 namespace SSS
 {
     namespace UnityFileDebug
@@ -12,16 +12,16 @@ public class LogOutput
             public string tm; //time
             public string l;  //log
             public string s;  //stack
-        }
-
+        }
+
         public enum FileType
         {
             CSV,
             JSON,
             TSV,
             TXT
-        }
-
+        }
+
         [ExecuteInEditMode]
         public class UnityFileDebug : MonoBehaviour
         {
@@ -115,8 +115,16 @@ void HandleLog(string logString, string stackTrace, LogType type)
                 else
                 {
                     int end = logString.IndexOf("]");
-                    output.t = logString.Substring(1, end - 1);
-                    output.l = logString.Substring(end + 2);
+                    if (end > 1)
+                    {
+                        output.t = logString.Substring(1, end - 1);
+                        output.l = logString.Substring(end + 2);
+                    }
+                    else
+                    {
+                        output.t = type.ToString();
+                        output.l = logString;
+                    }
                 }
 
                 output.s = stackTrace;
@@ -145,4 +153,4 @@ void HandleLog(string logString, string stackTrace, LogType type)
             }
         }
     }
-}
+}