component/icu: Fix FTBFS with glibc >= 2.26.

https://sourceware.org/glibc/wiki/Release/2.26#Removal_of_.27xlocale.h.27

component/icu/buildout.cfg

@@ -14,6 +14,8 @@ configure-options =
   --prefix=${:location}
   --disable-static
   --enable-rpath
+patches =
+  ${:_profile_base_location_}/fix-glibc2.26-ftbfs.patch#f1622be16964029fc66a70b8f9e1693c
 
 [icu4c-slaposgcc]
 # need for onlyoffice-core

component/icu/fix-glibc2.26-ftbfs.patch

+--- source/i18n/digitlst.cpp	2018-03-29 10:59:45.706746334 +0900
++++ source/i18n/digitlst.cpp	2018-03-29 11:01:15.933534983 +0900
+@@ -61,11 +61,7 @@
+ #endif
+ 
+ #if U_USE_STRTOD_L
+-# if U_PLATFORM_USES_ONLY_WIN32_API || U_PLATFORM == U_PF_CYGWIN
+-#   include <locale.h>
+-# else
+-#   include <xlocale.h>
+-# endif
++# include <locale.h>
+ #endif
+ 
+ // ***************************************************************************