This function replaces the one that checked whether there is a subnet for
an interface and returns boolean value.

This reverts commit b00635aa. The
previous alignment was correct (see ticket #1516 comment 7 and 8).

This gives us a very tiny speedup, as size() was a const method already.

Branch trac2904_v3 has been merged to master. This test was written
before that merge and uses the old port number. Use the new port
56176 instead.

Where a definition list is used to discuss function parameters, use
the <code> modifier to make it more clear that the definition
term is discussing a variable in the function signature mentioned
above the definition list.