Widen network error message

[Airiinnn]

Fixes #266

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Files with missing lines	Coverage Δ	Complexity Δ
...in/java/seedu/address/model/addresses/Network.java	100.00% <ø> (ø)	1.00 <0.00> (ø)