Update tracing-appender/src/rolling.rs

Co-authored-by: Peter Holloway <[email protected]>

Author: kaffarell

tracing-appender/src/rolling.rs

@@ -605,7 +605,8 @@ impl Inner {
                 let created = metadata.created().ok().or_else(|| {
                     let mut datetime = filename;
                     if let Some(prefix) = &self.log_filename_prefix {
-                        datetime = datetime.strip_prefix(&format!("{prefix}."))?;
+                        datetime = datetime.strip_prefix(prefix)?;
+                        datetime = datetime.strip_prefix('.')?;
                     }
                     if let Some(suffix) = &self.log_filename_suffix {
                         datetime = datetime.strip_suffix(&format!(".{suffix}"))?;