algo: covers: Fix memory leaks of approximate enhanced covers computation

alib2algo/src/stringology/cover/ApproximateEnhancedCoversComputation.h

@@ -42,8 +42,10 @@ ext::set < string::LinearString < SymbolType > > ApproximateEnhancedCoversComput
 	for ( size_t i = 2; i < x.getContent ( ).size ( ); ++i ) {
 		nextState = constrNextState ( x, previousState, k );
-		if ( nextState->elements.size ( ) < 2 )
+		if ( nextState->elements.size ( ) < 2 ) {
+			delete nextState;
 			break;
+		}
 		delete previousState;
 		Element lastElement = nextState->elements[nextState->elements.size ( ) - 1];