AZL-35102 CVE-2018-20969 affecting package patch for versions less than 2.7.6-9

doedscript in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character. NOTE: this is the same commit as for CVE-2019-13638, but the ! syntax is specific to ed, and is unrelated to a shell metacharacter...