[gnome-builder] configure: Consistently use autoconf conditionals

[Christian Hergert <chergert src gnome org>]

commit cab1c5e5ded587d731a4fb4a3065962c9c92b226
Author: Patrick Griffis <tingping tingping se>
Date:   Thu Apr 30 15:36:29 2015 -0400

    configure: Consistently use autoconf conditionals

 configure.ac |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f7df2a2..b412b43 100644
--- a/configure.ac
+++ b/configure.ac
@@ -163,9 +163,9 @@ dnl ***********************************************************************
 dnl Check for Required Python
 dnl ***********************************************************************
 AC_PATH_TOOL(PYTHON3_CONFIG, "python3-config")
-if test -z "${PYTHON3_CONFIG}"; then
+AS_IF([test -z "${PYTHON3_CONFIG}"],[
   AC_MSG_ERROR([Failed to locate python3-config.])
-fi
+])
 LIBIDE_CFLAGS="${LIBIDE_CFLAGS} `${PYTHON3_CONFIG} --cflags`"
 LIBIDE_LIBS="${LIBIDE_LIBS} `${PYTHON3_CONFIG} --libs`"
 LIBIDE_LDFLAGS="${LIBIDE_LDFLAGS} `${PYTHON3_CONFIG} --ldflags`"