Address comment

Author: wschin

src/Microsoft.ML.Transforms/Text/NgramHashingTransformer.cs

@@ -946,7 +946,8 @@ public ColumnOptions(string name,
                     throw Contracts.ExceptParam(nameof(numberOfBits), $"Cannot support invertHash for a {0} bit hash. 30 is the maximum possible.", numberOfBits);
 
                 if (ngramLength == 1 && skipLength != 0)
-                    throw Contracts.ExceptUserArg(nameof(skipLength), $"Number of skips can only be zero when the maximum n-gram's length is one.");
+                    throw Contracts.ExceptUserArg(nameof(skipLength), string.Format(
+                        "{0} (actual value: {1}) can only be zero when {2} set to one.", nameof(skipLength), skipLength, nameof(ngramLength)));
                 if (ngramLength + skipLength > NgramBufferBuilder.MaxSkipNgramLength)
                 {
                     throw Contracts.ExceptUserArg(nameof(skipLength),

src/Microsoft.ML.Transforms/Text/NgramTransform.cs

@@ -847,7 +847,8 @@ internal ColumnOptions(string name,
                 string inputColumnName = null)
             {
                 if (ngramLength == 1 && skipLength != 0)
-                    throw Contracts.ExceptUserArg(nameof(skipLength), $"Number of skips can only be zero when the maximum n-gram's length is one.");
+                    throw Contracts.ExceptUserArg(nameof(skipLength), string.Format(
+                        "{0} (actual value: {1}) can only be zero when {2} set to one.", nameof(skipLength), skipLength, nameof(ngramLength)));
                 if (ngramLength + skipLength > NgramBufferBuilder.MaxSkipNgramLength)
                     throw Contracts.ExceptUserArg(nameof(skipLength),
                         $"The sum of skipLength and ngramLength must be less than or equal to {NgramBufferBuilder.MaxSkipNgramLength}");