set rotation interval to float type as it should have been to start with

diff --git a/pykeylogger.val b/pykeylogger.val
index d673f1b..c9c4072 100644
--- a/pykeylogger.val
+++ b/pykeylogger.val
@@ -44,7 +44,7 @@ Log File Field Separator = string(default="|")

 # default: 4.0
 Log Rotation Interval Tooltip = string()
-Log Rotation Interval = string(min=0.016, default=4.0)
+Log Rotation Interval = float(min=0.016, default=4.0)

 # default: 120
 Flush Interval Tooltip = string()