Don't push empty rows

The current NEWLINE behavior of reading as much CR/LF as possible
basically means empty rows are/should be ignored.
This fixes the issue of pushing an empty row that can occur when the
data chunk ends in the middle of such a CR/LF stream (either because of
a block of empty lines or if you are unlucky because the chunk ended
right in the middle of a Windows CRLF endline)

Author: sjoubert

single_include/csv.hpp

@@ -7084,9 +7084,11 @@ namespace csv {
                     while (this->data_pos < in.size() && parse_flag(in[this->data_pos]) == ParseFlags::NEWLINE)
                         this->data_pos++;
 
-                    // End of record -> Write record
-                    this->push_field();
-                    this->push_row();
+                    // End of record -> Write non-empty record
+                    if (!this->current_row.empty()) {
+                        this->push_field();
+                        this->push_row();
+                    }
 
                     // Reset
                     this->current_row = CSVRow(data_ptr, this->data_pos, fields->size());