weechat: re-add inreplace "-u _PyMac_Error" flags.

this will fix Homebrew/legacy-homebrew#26610 which failed the build with error:

    no such file or directory: 'Python.framework/Versions/2.7/Python'

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/weechat.rb

@@ -19,6 +19,11 @@ class Weechat < Formula
   option 'with-ruby', 'Build the ruby module'
 
   def install
+    # this will fix error:
+    #    no such file or directory: 'Python.framework/Versions/2.7/Python'
+    inreplace 'src/plugins/python/CMakeLists.txt',
+      '${PYTHON_LFLAGS}', '-u _PyMac_Error'
+
     args = std_cmake_args + %W[
       -DPREFIX=#{prefix}
       -DENABLE_GTK=OFF