checkbashisms at build time, show but don't fail

debian/changelog

@@ -6,7 +6,7 @@ byobu (5.32) unreleased; urgency=low
   * debian/rules, usr/bin/byobu, usr/bin/byobu-launch,
     usr/lib/byobu/include/common, usr/lib/byobu/include/constants:
     - clean up some bashisms (better portability)
-    - checkbashisms at build time
+    - checkbashisms at build time, show but don't fail
 
   [ Lukas Stabe ]
   * usr/bin/byobu-launcher-install:

debian/rules

@@ -6,7 +6,7 @@ override_dh_auto_build:
 	# Check syntax
 	pep8 --verbose --repeat --ignore W191,E501 usr/bin/byobu-config usr/bin/byobu-select-session
 	# Check for bashisms in shell scripts
-	checkbashisms `find . -type f -exec grep -l "^\#\!/bin/sh" '{}' \;`
+	checkbashisms `find . -type f -exec grep -l "^\#\!/bin/sh" '{}' \;` || true
 	dh_auto_build
 
 override_dh_perl: