YCM: fix include paths

.ycm_extra_conf.py

@@ -38,7 +38,6 @@ flags = [
 '-Wall',
 '-Wextra',
 '-Werror',
-'-Wc++98-compat',
 '-Wno-long-long',
 '-Wno-variadic-macros',
 '-fexceptions',
@@ -59,9 +58,9 @@ flags = [
 # For a C project, you would set this to 'c' instead of 'c++'.
 '-x',
 'c++',
-'-isystem',
+'-I',
 '~/ndless/ndless-sdk/include',
-'-isystem',
+'-I',
 '~/.ndless/include',
 '-I',
 'include',