Fix generic typing of Tables.wrap

The T variable for the map values is bound when the method is called.
So the T will always refer exactly to the type of values the compiler
knows the passed object to contain. I think there is no need to use
"? extends T" and I am guessing it could cause problems downstream.

Author: ctrueden

src/main/java/org/scijava/table/Tables.java

@@ -57,10 +57,11 @@ private Tables() {
 	 * @param data The data to wrap. Each list element is a row; maps go from
 	 *          column name to data.
 	 * @param rowHeaders List of row header labels. Pass null for no row headers.
+	 * @param <T> The type of data in each cell of the table.
 	 * @return A {@link Table} object wrapping the data structure.
 	 */
 	public static <T> Table<Column<T>, T> wrap(
-		final List<? extends Map<?, ? extends T>> data, final List<String> rowHeaders)
+		final List<? extends Map<?, T>> data, final List<String> rowHeaders)
 	{
 		if (data.isEmpty()) throw new IllegalArgumentException("Cannot wrap an empty list");