Add check for allowableActions in firmware store

Using optional chaining to  test that TFTP is included in the
allowaableActions property to prevent an error being thrown if that
property is not present.

Signed-off-by: Derick Montague <derick.montague@ibm.com>
Change-Id: If0009810aaf3b9abd23fcdc41606fbdbcf17a347
diff --git a/src/store/modules/Configuration/FirmwareStore.js b/src/store/modules/Configuration/FirmwareStore.js
index 3b4bd85..c6639ff 100644
--- a/src/store/modules/Configuration/FirmwareStore.js
+++ b/src/store/modules/Configuration/FirmwareStore.js
@@ -115,7 +115,7 @@
             ];
 
           commit('setApplyTime', applyTime);
-          if (allowableActions.includes('TFTP')) {
+          if (allowableActions?.includes('TFTP')) {
             commit('setTftpUploadAvailable', true);
           }
         })