Revert "test: Break on test script (or other) error"

This reverts commit f22a7ec1e2.

Interrupting the test suite due to an actual bug in a test script
would be just fine, but interrupting the run of the entire test suite
at the first test failure is unacceptable.

test/notmuch-test

@@ -14,20 +14,12 @@ if [ ${BASH_VERSINFO[0]} -lt 4 ]; then
     exit 1
 fi
 
-set -e
-
-die () {
-    echo >&2 "Unexpected failure"
-}
-
-trap 'die' 0
-
 cd $(dirname "$0")
 
 TESTS="basic new search search-output json thread-naming raw reply dump-restore uuencode thread-order author-order from-guessing long-id encoding emacs maildir-sync"
 
 # Clean up any results from a previous run
-rm -rf test-results >/dev/null 2>/dev/null
+rm -r test-results >/dev/null 2>/dev/null
 
 # Run the tests
 for test in $TESTS; do
@@ -39,5 +31,3 @@ done
 
 # Clean up
 rm -r test-results corpus.mail
-
-trap '' 0