Revert "Pin rdoc to fix-stopdoc-reset-in-c-parser branch"

This reverts commit 8a3d53c.

Author: st0012

gems/bundled_gems

@@ -37,7 +37,7 @@ ostruct             0.6.3   https://github.com/ruby/ostruct
 pstore              0.2.1   https://github.com/ruby/pstore
 benchmark           0.5.0   https://github.com/ruby/benchmark
 logger              1.7.0   https://github.com/ruby/logger
-rdoc                7.2.0   https://github.com/ruby/rdoc 2bce3911a91bef2c0e6812e8ea38cf14e0f18fac
+rdoc                7.2.0   https://github.com/ruby/rdoc e4e332f2857f37f04f2f0aa359ce269a2c624176
 win32ole            1.9.3   https://github.com/ruby/win32ole
 irb                 1.17.0  https://github.com/ruby/irb
 reline              0.6.3   https://github.com/ruby/reline