Use template string for nansQueryTpl

lib/cartodb/models/dataview/histogram.js

@@ -145,14 +145,14 @@ const infinitiesQueryTpl = ctx => `
     )
 `;
 
-var nansQueryTpl = dot.template([
-    '__cdb_nans AS (',
-    '  SELECT',
-    '    count(*) AS __cdb_nans_count',
-    '  FROM ({{=it._query}}) __cdb_nans_query',
-    '  WHERE {{=it._column}} = \'NaN\'::float',
-    ')'
-].join('\n'));
+const nansQueryTpl = ctx => `
+    __cdb_nans AS (
+        SELECT
+            count(*) AS __cdb_nans_count
+        FROM (${ctx._query}) __cdb_nans_query
+        WHERE ${ctx._column} = 'NaN'::float
+    )
+`;
 
 var histogramQueryTpl = dot.template([
     'SELECT',