tests: Trim .nim files trailing whitespace

via OSX: find . -name '*.nim' -exec sed -i '' -E 's/[[:space:]]+$//' {} +

tests/method/tmultim1.nim

@@ -10,7 +10,7 @@ type
     x: int
   PlusExpr = ref object of Expression
     a, b: Expression
-    
+
 method eval(e: Expression): int = quit "to override!"
 method eval(e: Literal): int = return e.x
 method eval(e: PlusExpr): int = return eval(e.a) + eval(e.b)
@@ -18,7 +18,7 @@ method eval(e: PlusExpr): int = return eval(e.a) + eval(e.b)
 proc newLit(x: int): Literal =
   new(result)
   result.x = x
-  
+
 proc newPlus(a, b: Expression): PlusExpr =
   new(result)
   result.a = a