SPI entires dup by 3 times.

[beiwei30]

Recently, a user commit a issue[1] about that the dubbo.internal's files
has repeated content like this:

netty=com.alibaba.dubbo.remoting.transport.netty.NettyTransporter
netty4=com.alibaba.dubbo.remoting.transport.netty4.NettyTransporter
mina=com.alibaba.dubbo.remoting.transport.mina.MinaTransporter
grizzly=com.alibaba.dubbo.remoting.transport.grizzly.GrizzlyTransporter

netty=com.alibaba.dubbo.remoting.transport.netty.NettyTransporter
netty4=com.alibaba.dubbo.remoting.transport.netty4.NettyTransporter
mina=com.alibaba.dubbo.remoting.transport.mina.MinaTransporter
grizzly=com.alibaba.dubbo.remoting.transport.grizzly.GrizzlyTransporter

netty=com.alibaba.dubbo.remoting.transport.netty.NettyTransporter
netty4=com.alibaba.dubbo.remoting.transport.netty4.NettyTransporter
mina=com.alibaba.dubbo.remoting.transport.mina.MinaTransporter
grizzly=com.alibaba.dubbo.remoting.transport.grizzly.GrizzlyTransporter

Looks like the entries are dup by 3 times, see details from #2828

[carryxyh]

Hi, @beiwei30
I can't reproduce this on my mac.
I use this command: mvn clean install -Prelease -Dmaven.test.skip=true (before this, I have remove the maven-gpg-plugin).

After doing install, the spi file in dubbo-all/target/ looks nice...

[chickenlj]

I also tried locally, but cannot reproduce.

1. clone dubbo-2.6.4 tag
2. run mvn clean install -DskipTests

[beiwei30]

I cannot reproduce it either on 2.6.5

[mercyblitz]

It's present in the binary and source jar files of 2.6.5.