configure: always print ac_cv_c_compiler_gnu

Previously, we only printed whether the used compiler was
detected as gcc if the answer was positive. Now we always
print the result (but the GCC version still is only
printed when we are using GCC)

Signed-off-by: Max Horn <max@quendi.de>
diff --git a/configure.ac b/configure.ac
index 1c936b3..abc1640 100644
--- a/configure.ac
+++ b/configure.ac
@@ -474,7 +474,7 @@
     Host OS : ............................. ${host_os}
 ])
 
-if test x$ac_cv_c_compiler_gnu = xyes ; then
 	echo "    Compiler is GCC : ..................... ${ac_cv_c_compiler_gnu}"
+if test x$ac_cv_c_compiler_gnu = xyes ; then
 	echo "    GCC version : ......................... ${GCC_VERSION}"
-	fi
+fi