Remove unnecessary '-r' option from 'ln' command.

For this particular case, we do not have to specify '-r' option.
Even if we remove '-r' option here, exactly the same symlink will be
created in practice.

Not relying on '-r' option is convenient since '-r' option does not work
with older versions of 'ln' command.  In particular, that option does
not work on Ubuntu 12.04, which prevents us from enabling Android build
on Travis-CI.

This is just a code clean up in build rules.  No behavior change in
artifacts should occur.

BUG=none
TEST=compile
REF_BUG=none
REF_CL=105034319

src/android/resources/resources.gyp

@@ -153,7 +153,7 @@
             'dummy_make_symbolic_link',
           ],
           'action': [
-            'ln', '-r', '-s', '-f',
+            'ln', '-s', '-f',
             '<(sdk_resources_dir)/res',
             'res',
           ],

src/mozc_version_template.txt

@@ -1,6 +1,6 @@
 MAJOR=2
 MINOR=17
-BUILD=2125
+BUILD=2126
 REVISION=102
 # NACL_DICTIONARY_VERSION is the target version of the system dictionary to be
 # downloaded by NaCl Mozc.