(Bug 50263) Conclude why a.args in sometimes undefined

 * A few lines above we're pushing an object like { wt: "" } into the
   tplArray.

 * Confirmed this was the case in zhwiki/阿塔瓦爾帕?oldid=26962571 when
   33dd016419f51750c73d1cbabee7dfccc399ba3b landed.

Change-Id: Ic99c338291db4f2728abacce1c62242465f89124