fix rounding to 0 decimals (#5)

* fix rounding to 0 decimals

will give full mg/dL targets and mmol/L will just convert fine, also setting in mmol/L works as intended in single decimal digits

* also adapt save function

FreeAPS/Sources/Modules/AddTempTarget/AddTempTargetStateModel.swift

@@ -40,7 +40,7 @@ extension AddTempTarget {
                     target = (c / ratio) - c + 100
                 }
                 lowTarget = target
-                lowTarget = Decimal(round(Double(target * 10)) / 10)
+                lowTarget = Decimal(round(Double(target)))
             }
             var highTarget = lowTarget
 
@@ -81,7 +81,7 @@ extension AddTempTarget {
                     target = (c / ratio) - c + 100
                 }
                 lowTarget = target
-                lowTarget = Decimal(round(Double(target * 10)) / 10)
+                lowTarget = Decimal(round(Double(target)))
             }
             var highTarget = lowTarget