Add CTPP2 patch to correctly handle ICONV_SUPPORT variable.

If there is no ICONV_SUPPORT, we must not try to compile stuff relative
to iconv.

kiwix-build.py

@@ -810,7 +810,8 @@ class CTPP2(Dependency):
                "ctpp2_fix-static-libname.patch",
                "ctpp2_mingw32.patch",
                "ctpp2_dll_export_VMExecutable.patch",
-               "ctpp2_win_install_lib_in_lib_dir.patch"]
+               "ctpp2_win_install_lib_in_lib_dir.patch",
+               "ctpp2_iconv_support.patch"]
 
     class Builder(CMakeBuilder):
         configure_option = "-DMD5_SUPPORT=OFF"

patches/ctpp2_iconv_support.patch

@@ -0,0 +1,20 @@
+diff -ur ctpp2-2.8.3/src/CTPP2StringIconvOutputCollector.cpp ctpp2-2.8.3.iconv/src/CTPP2StringIconvOutputCollector.cpp
+--- ctpp2-2.8.3/src/CTPP2StringIconvOutputCollector.cpp	2017-02-07 10:42:40.567806420 +0100
++++ ctpp2-2.8.3.iconv/src/CTPP2StringIconvOutputCollector.cpp	2017-01-30 15:22:19.734186564 +0100
+@@ -38,6 +38,8 @@
+ namespace CTPP // C++ Template Engine
+ {
+ 
++
++#ifdef ICONV_SUPPORT
+ //
+ // Constructor
+ //
+@@ -114,5 +116,7 @@
+ return 0;
+ }
+ 
++#endif //ICONV_SUPPORT
++
+ } // namespace CTPP
+ // End.