CDRIVER-4132 update RPM spec patch post-1.19.0 release

Author: rcsanchez97

.evergreen/spec.patch

@@ -5,7 +5,7 @@
  %global libname      libmongoc
  %global libver       1.0
 -%global up_version   1.18.0
-+%global up_version   1.19.0
++%global up_version   1.20.0
  #global up_prever    rc0
  # disabled as require a MongoDB server
  %bcond_with          tests