debian/changelog: UNRELEASED => experimental

Gbp-Dch: Ignore

debian/changelog

-openexr (2.5.1-1) UNRELEASED; urgency=medium
+openexr (2.5.1-1) experimental; urgency=medium
 
   * New upstream release (Closes: #960439)
     - debian/control: SONAME bump 24 -> 25
   * debian/rules: set cmake as build system
 
- -- Matteo F. Vescovi <mfv@debian.org>  Thu, 21 May 2020 22:43:24 +0200
+ -- Matteo F. Vescovi <mfv@debian.org>  Thu, 21 May 2020 23:05:36 +0200
 
 openexr (2.5.0-1) experimental; urgency=medium