config.h: fix check for appindicator

If appindicator lib is not found APPINDICATOR_FOUND variable is not
set by cmake. Thus HAVE_APPINDICATOR in config.h is not set. This
seems to default to 0 in the pre-processor, and thus to true. So in
this case we try to build with appindicator, even though it doesn't
exist.

We fix this by explicitly setting HAVE_APPINDICATOR to 0 or 1.

Change-Id: I50baf0262f95f899262c71f70783dcccb11c53ee
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9fd7a59..83c747a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -415,6 +415,13 @@
    SET(USE_LIBNM 0)
 ENDIF()
 
+# configure appindicator variable for config.h file
+IF( APPINDICATOR_FOUND )
+    SET(HAVE_APPINDICATOR 1)
+ELSE()
+    SET(HAVE_APPINDICATOR 0)
+ENDIF()
+
 # create config header file to pass cmake settings to source code
 CONFIGURE_FILE (
    "${PROJECT_SOURCE_DIR}/src/config.h.in"