tests: Check if CXX is "no", not ":"

* lang-c++: Check if CXX is "no", not ":".  See commit e854d2c7 for
the rationale.

gettext-tools/tests/ChangeLog

@@ -1,3 +1,8 @@
+2014-10-03  Daiki Ueno  <ueno@gnu.org>
+
+	* lang-c++: Check if CXX is "no", not ":".  See commit e854d2c7
+	for the rationale.
+
 2014-10-02  Daiki Ueno  <ueno@gnu.org>
 
 	* autopoint-3: Invoke AC_CONFIG_MACRO_DIR after AC_INIT, not

gettext-tools/tests/lang-c++

@@ -6,7 +6,7 @@
 # Assumes the following packages are installed: gcc g++.
 
 # Test whether a C++ compiler is found and libasprintf is built.
-test "${CXX}" != ":" || {
+test "${CXX}" != "no" || {
   echo "Skipping test: no C++ compiler found"
   exit 77
 }