fixed test input code and removed unused import

src/afterfact.rs

@@ -795,7 +795,7 @@ mod tests {
                 (
                     "%Channel%".to_owned(),
                     mock_ch_filter
-                        .get("security")
+                        .get(&"Security".to_ascii_lowercase())
                         .unwrap_or(&String::default())
                         .to_string(),
                 ),

src/detections/detection.rs

@@ -25,7 +25,6 @@ use crate::filter;
 use crate::yaml::ParseYaml;
 use hashbrown::HashMap;
 use serde_json::Value;
-use std::ascii::AsciiExt;
 use std::fmt::Write;
 use std::path::Path;
 

src/detections/message.rs

@@ -599,7 +599,7 @@ mod tests {
         let actual = create_output_filter_config("test_files/config/channel_abbreviations.txt");
         let actual2 = create_output_filter_config("test_files/config/channel_abbreviations.txt");
         let expected: HashMap<String, String> = HashMap::from([
-            ("security".to_string(), "Sec".to_string()),
+            ("Security".to_ascii_lowercase(), "Sec".to_string()),
             ("xxx".to_string(), "yyy".to_string()),
         ]);
         _check_hashmap_element(&expected, actual);