disable broken test mingw debug

"g++"   -fvisibility-inlines-hidden -m32 -mthreads -O0 -fno-inline -Wall -g -fvisibility=hidden -march=i686 -Wextra -Wno-long-long -Wno-unused-parameter -Wno-variadic-macros -Wunused-function -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED -DBOOST_THREAD_USE_DLL=1 -DBOOST_THREAD_WIN32  -I"."  -c -o "bin.v2\libs\thread\test\ex_executor.test\gcc-5\dbg\thrdp-wn32\thrd-mlt\vsblt-hdn\executor.o" "libs\thread\test\..\example\executor.cpp"
...failed gcc.compile.c++ bin.v2\libs\thread\test\ex_executor.test\gcc-5\dbg\thrdp-wn32\thrd-mlt\vsblt-hdn\executor.o...

https://ci.appveyor.com/project/pdimov/thread/builds/40207198/job/qu7mtpfr0lngi6ca

Author: makelinux

appveyor.yml

@@ -45,9 +45,10 @@ environment:
       TOOLSET: gcc
       VARIANT: release
 
-    - ADDPATH: C:\mingw\bin;
-      TOOLSET: gcc
-      VARIANT: debug
+#      FIXME:
+#    - ADDPATH: C:\mingw\bin;
+#      TOOLSET: gcc
+#      VARIANT: debug
 
 # The following configurations fail with
 # ./boost/thread/detail/invoke.hpp:101:43: internal compiler error: in gimplify_expr, at gimplify.c:12039