squid: install systemd unit without executable bit

install defaults to mode 0755, which makes systemd complain:

  Configuration file /usr/lib/systemd/system/squid.service is marked
  executable. Please remove executable permission bits. Proceeding anyway.

Signed-off-by: Patrick Wicki <patrick.wicki@siemens.com>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-networking/recipes-daemons/squid/squid_7.7.bb

@@ -117,7 +117,7 @@ do_install:append() {
     if ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'true', 'false', d)}; then
         # Install service unit file
         install -d ${D}/${systemd_unitdir}/system
-        install ${S}/tools/systemd/squid.service ${D}/${systemd_unitdir}/system
+        install -m 0644 ${S}/tools/systemd/squid.service ${D}/${systemd_unitdir}/system
         sed -i 's:/var/run/:/run/:g' ${D}/${systemd_unitdir}/system/squid.service
 
         # Configure tmpfiles.d