fill-paragraph puts one useless blank at the end of many Chinese big5 lines

[Dan Jacobson]

fill-paragraph puts one useless blank at the end of many of these
Chinese big5 lines here in locale zh_TW.Big5 when I set fill-column to
16 or 17 etc. I uuencoded the sample input:

begin 644 big5.txt
MI;ND2*GS(`IH='1P.B\O:FED86YN:2YO<F<O8V]M;2]R861I;R]F<F5Q+R`*
MMDO$M;GNH4*N^*B^H4*QSPK%0#H@IE6_I*6KI,"GO:%""JE)N+FD0,3]JNVA
M0:7^K-D*Q+6EK:UPN;K`5[)VJNVA02`*I72FLZ5XI5^MN*_HL:&S^`JPSZ_H
IJL6S<;!4P%>Y1*KMH4,@"KNPI]:D5;C\H4$@N%6D0+-1"JO*PNJA0PH`
`
end
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