fix base64 decoding command in keytab (#1995)

Author: kevinAlbs

.evergreen/config_generator/components/funcs/prepare_kerberos.py

@@ -14,7 +14,7 @@ class PrepareKerberos(Function):
             script='''\
             if test "${keytab|}" && command -v kinit >/dev/null; then
                 echo "${keytab}" > /tmp/drivers.keytab.base64
-                base64 --decode /tmp/drivers.keytab.base64 > /tmp/drivers.keytab
+                cat /tmp/drivers.keytab.base64 | base64 -d > /tmp/drivers.keytab
                 if touch /etc/krb5.conf 2>/dev/null; then
                     cat .evergreen/etc/kerberos.realm | tee -a /etc/krb5.conf
                 elif command sudo true 2>/dev/null; then

.evergreen/generated_configs/functions.yml

@@ -339,7 +339,7 @@ functions:
           - |
             if test "${keytab|}" && command -v kinit >/dev/null; then
                 echo "${keytab}" > /tmp/drivers.keytab.base64
-                base64 --decode /tmp/drivers.keytab.base64 > /tmp/drivers.keytab
+                cat /tmp/drivers.keytab.base64 | base64 -d > /tmp/drivers.keytab
                 if touch /etc/krb5.conf 2>/dev/null; then
                     cat .evergreen/etc/kerberos.realm | tee -a /etc/krb5.conf
                 elif command sudo true 2>/dev/null; then