common.mk: update dependency

* common.mk: update dependency of string.o to id.h for r52479.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52482 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -2196,6 +2196,7 @@ string.$(OBJEXT): {$(VPATH)}defines.h
 string.$(OBJEXT): {$(VPATH)}encindex.h
 string.$(OBJEXT): {$(VPATH)}encoding.h
 string.$(OBJEXT): {$(VPATH)}gc.h
+string.$(OBJEXT): {$(VPATH)}id.h
 string.$(OBJEXT): {$(VPATH)}intern.h
 string.$(OBJEXT): {$(VPATH)}internal.h
 string.$(OBJEXT): {$(VPATH)}io.h