libical: Try out patch to fix PACKAGE_DATA_DIR

Without this patch the path compiled into the library is actually

  "/data/data/com.termux/files/usr/share/libical"/zoneinfo

with the extra quotes. This patch makes it

  /data/data/com.termux/files/usr/share/libical/zoneinfo

which will hopefully make the library work without calling
set_zone_directory(). See #1913.

packages/libical/build.sh

@@ -1,7 +1,7 @@
 TERMUX_PKG_HOMEPAGE=http://libical.github.io/libical/
 TERMUX_PKG_DESCRIPTION="Libical is an Open Source implementation of the iCalendar protocols and protocol data units"
 TERMUX_PKG_VERSION=3.0.1
-TERMUX_PKG_REVISION=1
+TERMUX_PKG_REVISION=2
 TERMUX_PKG_SRCURL=https://github.com/libical/libical/releases/download/v$TERMUX_PKG_VERSION/libical-$TERMUX_PKG_VERSION.tar.gz
 TERMUX_PKG_DEPENDS="libxml2"
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS=" -DSHARED_ONLY=true -DICAL_GLIB=false -DUSE_BUILTIN_TZDATA=true"

packages/libical/src-libical-CMakeLists.txt.patch

@@ -0,0 +1,12 @@
+diff -u -r ../libical-3.0.1/src/libical/CMakeLists.txt ./src/libical/CMakeLists.txt
+--- ../libical-3.0.1/src/libical/CMakeLists.txt	2017-11-19 15:32:53.000000000 +0100
++++ ./src/libical/CMakeLists.txt	2017-12-09 22:14:42.254898817 +0100
+@@ -17,7 +17,7 @@
+   include_directories(${ICU_INCLUDE_DIR})
+ endif()
+ 
+-set(PACKAGE_DATA_DIR "\\\"${CMAKE_INSTALL_PREFIX}/share/libical\\\"")
++set(PACKAGE_DATA_DIR "${CMAKE_INSTALL_PREFIX}/share/libical")
+ add_definitions(-DPACKAGE_DATA_DIR="${PACKAGE_DATA_DIR}")
+ 
+ set(ICALSCRIPTS ${CMAKE_SOURCE_DIR}/scripts/)