fget_input_string(): Fix condition for console reading (Cygwin/MinGW)
fget_input_string(): Fix condition for console reading (Cygwin/MinGW)

opencog/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,linas/link-grammar,opencog/link-grammar,opencog/link-grammar,opencog/link-grammar,opencog/link-grammar,opencog/link-grammar,linas/link-grammar,linas/link-grammar,opencog/link-grammar,ampli/link-grammar,ampli/link-grammar,linas/link-grammar,ampli/link-grammar,opencog/link-grammar,linas/link-grammar,linas/link-grammar,linas/link-grammar,ampli/link-grammar,opencog/link-grammar,ampli/link-grammar