Merge #1128: configure: Remove pkgconfig macros again (reintroduced by mismerge)

cabe085 configure: Remove pkgconfig macros again (reintroduced by mismerge) (Tim Ruffing)

Pull request description:

  We had removed `PKG_PROG_PKG_CONFIG` in 21b2eba
  (#1090). But then then the not rebased (!) merge of 2be6ba0
  (#1084) brought that macro back at another location, without git
  complaining about a conflict.

  Fixes #1127.

ACKs for top commit:
  fanquake:
    ACK cabe085
  hebasto:
    ACK cabe085
  jonasnick:
    ACK cabe085

Tree-SHA512: ba497503db3a11e631b15c4fe875e62d892971c2c708d90b2f6be684e85d164043ea97c13af0452831eef41f3cf8230cd8a9eafa332dc5b5ae18e118b87c3828

Author: real-or-random

configure.ac

@@ -43,8 +43,6 @@ AS_UNSET(ac_cv_prog_AR)
 AS_UNSET(ac_cv_prog_ac_ct_AR)
 LT_INIT([win32-dll])
 
-PKG_PROG_PKG_CONFIG
-
 build_windows=no
 
 case $host_os in