fixed typo in abstract

main.tex

@@ -94,9 +94,9 @@ tabsize=2
 \begin{abstract}
 We apply model learning on three SSH implementations to infer state machine models, which
 are then verified by a model checker for functional and security properties. Our results show that 
-all tested SSH servers satisfy the security properties, but only
+all tested SSH servers satisfy the security properties, but 
 satisfy the functional properties
-only by a varying degree. Moreover, the state machines of the
+only to a varying degree. Moreover, the state machines of the
 implementations differ significantly, allowing them to be 
 effectively fingerprinted.