Fix that a incorrect attachment could be selected

If an attachment with id 1234 and 12345 exists for the same task, the
12345 attachment could be selected for both.

snapshotter.sh

@@ -68,7 +68,7 @@ function download() {
 
 function download_attachment() {
   local filename=""
-  if ! grep -q "^${1} ${2}" attachments/attachments.txt; then
+  if ! grep --quiet --max-count=1 "^${1} ${2} " attachments/attachments.txt; then
     rm -fr "attachments/${1}/tmp"
     mkdir -p "attachments/${1}/"{tmp,${2}}
     cd "attachments/${1}/tmp"
@@ -88,7 +88,7 @@ function download_attachment() {
     rmdir tmp
     cd ../../
   else
-    filename="$(grep "^${1} ${2}" attachments/attachments.txt | cut -f3- -d " ")"
+    filename="$(grep --max-count=1 "^${1} ${2} " attachments/attachments.txt | cut -f3- -d " ")"
   fi
 
   # https://unix.stackexchange.com/a/33005