Merge bitcoin/bitcoin#29579: build: bump version to 27.99

fd4fe41 build: bump version to 27.99 (fanquake)

Pull request description:

  27.x has been branched off.

ACKs for top commit:
  glozow:
    slow ACK fd4fe41
  theStack:
    ACK fd4fe41
  dergoegge:
    utACK fd4fe41

Tree-SHA512: 1550becd190c1a5195d3123a83b6ac790797c485e2dbbfb0f4cb0bc0a611d8331a553b94f2896cf8ac3755040d7532d9ee6e312bf3b8e4ca9a5adce6d00c484e

Author: fanquake

configure.ac

@@ -1,5 +1,5 @@
 AC_PREREQ([2.69])
-define(_CLIENT_VERSION_MAJOR, 26)
+define(_CLIENT_VERSION_MAJOR, 27)
 define(_CLIENT_VERSION_MINOR, 99)
 define(_CLIENT_VERSION_BUILD, 0)
 define(_CLIENT_VERSION_RC, 0)