Make relative-paths work with binary files

`relativize_path_maybe()` was not called in this case. Added test.

src/handlers/diff_header.rs

@@ -467,6 +467,8 @@ pub fn get_file_change_description_from_file_paths(
 
 #[cfg(test)]
 mod tests {
+    use insta::assert_snapshot;
+    use crate::tests::integration_test_utils::{make_config_from_args, DeltaTest};
     use super::*;
 
     #[test]
@@ -637,4 +639,42 @@ mod tests {
             Some(".config/Code - Insiders/User/settings.json".to_string())
         );
     }
+
+    pub const BIN_AND_TXT_FILE_ADDED: &str = "\
+diff --git a/BIN b/BIN
+new file mode 100644
+index 0000000..a5d0c46
+Binary files /dev/null and b/BIN differ
+diff --git a/TXT b/TXT
+new file mode 100644
+index 0000000..323fae0
+--- /dev/null
++++ b/TXT
+@@ -0,0 +1 @@
++plain text";
+
+    #[test]
+    fn test_diff_header_relative_paths() {
+        // rustfmt ignores the assert macro arguments, so do the setup outside
+        let mut cfg = make_config_from_args(&["--width=40", "--relative-paths"]);
+        cfg.cwd_relative_to_repo_root = Some("src/".into());
+        let result =
+            DeltaTest::with_config(&cfg)
+            .with_input(BIN_AND_TXT_FILE_ADDED)
+            .output;
+        assert_snapshot!(result, @r###"
+
+        added: ../BIN (binary file)
+        ────────────────────────────────────────
+
+        added: ../TXT
+        ────────────────────────────────────────
+
+        ───┐
+        1: │
+        ───┘
+        plain text
+        "###
+        );
+    }
 }

src/handlers/diff_header_misc.rs

@@ -1,4 +1,5 @@
 use crate::delta::{DiffType, Source, State, StateMachine};
+use crate::utils::path::relativize_path_maybe;
 
 impl<'a> StateMachine<'a> {
     #[inline]
@@ -29,9 +30,11 @@ impl<'a> StateMachine<'a> {
             }
 
             if self.minus_file != "/dev/null" {
+                relativize_path_maybe(&self.config, &mut self.minus_file);
                 self.minus_file.push_str(" (binary file)");
             }
             if self.plus_file != "/dev/null" {
+                relativize_path_maybe(&self.config, &mut self.plus_file);
                 self.plus_file.push_str(" (binary file)");
             }
             return Ok(true);

src/tests/test_example_diffs.rs

@@ -126,7 +126,6 @@ mod tests {
             "bash",
         ]);
         let output = integration_test_utils::run_delta(MODIFIED_BASH_AND_CSHARP_FILES, &config);
-        eprintln!("{}", &output);
         ansi_test_utils::assert_line_has_syntax_highlighted_substring(
             &output,
             19,