tests: Trim .nim files trailing whitespace

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

tests/manyloc/keineschweine/lib/zlib_helpers.nim

@@ -18,7 +18,7 @@ proc uncompress*(source: string, destLen: var int): string =
   var res = zlib.uncompress(cstring(result), addr destLen, cstring(source), source.len)
   if res != Z_OK:
     echo "Error occurred: ", res
-    
+
 
 when isMainModule:
   import strutils
@@ -37,4 +37,4 @@ when isMainModule:
   ln = s.len
   rr = uncompress(r, ln)
   echo r.len, " -> ", rr.len
-  assert rr == s
+  assert rr == s