[libphobos] Update MERGE file, remove ill-formatted changelog entry

Changelog entries are not required for upstream merges.

From-SVN: r269887

libphobos/ChangeLog

-2019-03-02  Johannes Pfau  <johannespfau@gmail.com>
-
-	* src/std/digest/murmurhash.d: PR d/89177: Backport from upstream.
-	Fixes unaligned data access (PR d/89177).
-
 2019-02-19  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* src/Makefile.am: Avoid the -D option which is not available

libphobos/src/MERGE

-791c5d2407e500bb4e777d6a90fc96cf250ba2f6
+ef07932811de50a1d5810ea23462d127a60574a6
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/phobos repository.