Fix fmt -j.
 [rsc] --rw-rw-r-- M 785568 glenda sys 4078 Jan 18 11:59 sys/src/cmd/fmt.c
	/n/sourcesdump/2006/0118/plan9/sys/src/cmd/fmt.c:210,216 - 
	/n/sourcesdump/2006/0119/plan9/sys/src/cmd/fmt.c:210,216
	  			nsp = nspaceafter(w[i-1]->text);
	  			if(col+nsp+utflen(w[i]->text) > extraindent+length)
	  				break;	/* fold line */
	- 			if(!join && n != 0 && w[i]->bol)
	+ 			if(!join && w[i]->bol)
	  				break;
	  			for(j=0; j<nsp; j++)
	  				Bputc(&bout, ' ');	/* emit space; another word will follow */