Amend getFullPathNoEndSeparator description for trailing slash home path behaviour

[Philzen]

The description says it will remove the trailing slash from a home path (relative path starting with tilde).

A simple

        @Test void returnsHomeWithTrailingSlash_forHomeWithTrailingSlash() {
            assertThat(FilenameUtils.getFullPathNoEndSeparator("~/")).isEqualTo("~/");
        }

proves otherwise.

This fixes the description accordingly. NB: this behaviour has been existent since 2.4, where i discovered it.

[Philzen]

Any objections merging this?