fix: handle UTF-8 files correctly when choosing between grep/zgrep

files/error-summary.sh

@@ -147,8 +147,10 @@ get_last_n_days(){
 			GREP_CMD="zgrep"
 		elif file -b "${LOGFILE}" | grep "ASCII text" > /dev/null; then
 			GREP_CMD="grep"
+		elif file -b "${LOGFILE}" | grep "UTF-8 Unicode text" > /dev/null; then
+			GREP_CMD="grep"
 		else
-			>&2 echo "ERROR: unknown filetype, cannot find error strings from file '${LOGFILE}.'"
+			>&2 echo "ERROR: unknown filetype, cannot find error strings from file '${LOGFILE}'."
 		fi
 		${GREP_CMD} -oP "${FILTER_STRING}" "${LOGFILE}"
 	done | \