Fix AWK array initialization error

- Initialize rcpts array properly to avoid scalar/array error
- Skip empty recipient strings in output formatting
- Ensures proper 2D array handling in AWK

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

legacy/exitrace/exitrace.sh

@@ -362,7 +362,10 @@ fi
 # AWK Analysis
 grep_chain | awk -v TO_RE="${TO_REGEX:-}" -v WANTDOM="${TARGET_DOMAIN:-}" -v MSGIDREQ="${MSGID:-}" -v FROMREQ="${FROM:-}" -v EXTRA="${GREPEXTRA:-}" '
 function trim(s){ sub(/^[ \t\r\n]+/, "", s); sub(/[ \t\r\n]+$/, "", s); return s }
-function add_rcpt(id, rc){ if (!(rc in rcpts[id])) rcpts[id][rc]=1 }
+function add_rcpt(id, rc){ 
+  if (!(id in rcpts)) rcpts[id][""] = ""
+  if (!(rc in rcpts[id])) rcpts[id][rc]=1 
+}
 
 BEGIN { FS=" " }
 
@@ -484,7 +487,9 @@ END {
     out_rcpts=""
     if (id in rcpts){
       for (r in rcpts[id]) {
-        out_rcpts = (out_rcpts=="" ? r : out_rcpts ", " r)
+        if (r != "") {
+          out_rcpts = (out_rcpts=="" ? r : out_rcpts ", " r)
+        }
       }
     }