Fix condition to set start and end years in enrollments route

Signed-off-by: João Victor Tozatti Risso <jvtr12@c3sl.ufpr.br>

libs/routes/api.js

@@ -78,7 +78,7 @@ router.get('/enrollments.:format?', function(req, res) {
     if (params.start_year)
     {
         start_year = parseInt(params.start_year, 10);
-    } else if (start_year > 0) {  // if start_year was not previously set
+    } else if (start_year == 0) {  // if start_year was not previously set
         var yearSql = "SELECT MIN(t.ano_censo) AS start_year FROM turmas AS t";
         conn.query(yearSql, true).then(function(result) {
             start_year = result.data.start_year;
@@ -88,7 +88,7 @@ router.get('/enrollments.:format?', function(req, res) {
     if (params.end_year)
     {
         end_year = parseInt(params.end_year, 10);
-    } else if (end_year > 0) {  // if end_year was not previously set
+    } else if (end_year == 0) {  // if end_year was not previously set
         var yearSql = "SELECT MAX(t.ano_censo) AS end_year FROM turmas AS t";
         conn.query(yearSql, true).then(function(result) {
             end_year = result.data.end_year;