Update RemappingHelper.cs
Changed Split parameters to handle hostnames containing semi-columns

A ROS_MASTER_URI such as http://10.13.235.67 passed as parameter remapping like __master:=http://10.13.235.67 would not be chunked correctly which leads the program to crash.
I added a second parameter to the Split function to only consider two chunks in the split operation.
Merge pull request #6 from smamessier/master

Changed Split parameters to handle hostnames containing semi-columns