Update icu4c to latest support version

Before this commit the icu4c repo was fetched from TheCharlatan's
repository. This step was made, because up until recently the source
code was hosted on sourceforge and their downloads proved very
unreliable. The origin is now the official icu4c repository.
Also remove some commented lines left over from development.

contrib/depends/packages/icu4c.mk

@@ -1,8 +1,8 @@
 package=icu4c
-$(package)_version=55.1
-$(package)_download_path=https://github.com/TheCharlatan/icu4c/archive
-$(package)_file_name=55.1.tar.gz
-$(package)_sha256_hash=1f912c54035533fb4268809701d65c7468d00e292efbc31e6444908450cc46ef
+$(package)_version=55.2
+$(package)_download_path=https://github.com/unicode-org/icu/releases/download/release-55-2/
+$(package)_file_name=$(package)-55_2-src.tgz
+$(package)_sha256_hash=eda2aa9f9c787748a2e2d310590720ca8bcc6252adf6b4cfb03b65bef9d66759
 $(package)_patches=icu-001-dont-build-static-dynamic-twice.patch
 
 define $(package)_set_vars
@@ -21,11 +21,6 @@ define $(package)_config_cmds
   $(MAKE) $($(package)_build_opts)
 endef
 
-#define $(package)_build_cmds
-#  cd source &&\
-   $(MAKE) $($((package)_build_opts) `nproc`
-#endef
-
 define $(package)_stage_cmds
   cd buildb &&\
   $(MAKE) $($(package)_build_opts) DESTDIR=$($(package)_staging_dir) install lib/*