wrap-for-bin.sh: regenerate bin-wrappers when switching branches

Commit e6e7530 (test helpers: move test-* to t/helper/ subdirectory -
2016-04-13) moves test-* to t/helper. However because bin-wrappers/*
only depend on wrap-for-bin.sh, when switching between a branch that has
this commit and one that does not, bin-wrappers/* may not be regenerated
and point to the old/outdated test programs.

This commit makes a non-functional change in wrap-for-bin.sh, just
enough for 'make' to detect and re-execute wrap-for-bin.sh. When
switching between a branch containing both this commit and e6e7530 and
one containing neither, bin-wrappers/*, we should get fresh bin-wrappers/*.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

wrap-for-bin.sh

@@ -17,6 +17,7 @@ fi
 GITPERLLIB='@@BUILD_DIR@@/perl/blib/lib'"${GITPERLLIB:+:$GITPERLLIB}"
 GIT_TEXTDOMAINDIR='@@BUILD_DIR@@/po/build/locale'
 PATH='@@BUILD_DIR@@/bin-wrappers:'"$PATH"
+
 export GIT_EXEC_PATH GITPERLLIB PATH GIT_TEXTDOMAINDIR
 
 if test -n "$GIT_TEST_GDB"