Remove explicit garbage collection

https://docs.pmd-code.org/pmd-doc-7.8.0/pmd_rules_java_errorprone.html#donotcallgarbagecollectionexplicitly

Author: pilafmon

src/java/org/snapbackup/utilities/ZipEngine.java

@@ -123,8 +123,6 @@ void logSkippedMsg(String msg) {
       }
 
    public void zipFile(String filePath) {
-      if (zipCount % 500 == 0)  //attempt to address performance issues on large backups
-          rt.gc();  //testing not yet done to see if this improves performance
       try {
          file = new File(filePath);
          String filename = file.getName();

tools/static-analysis/report.html

@@ -514,13 +514,7 @@
 <tr> 
 <td align="center">8</td>
 <td width="*%">snapbackup/src/java/org/snapbackup/utilities/ZipEngine.java</td>
-<td align="center" width="5%">127</td>
-<td width="*"><a href="https://docs.pmd-code.org/pmd-doc-7.8.0/pmd_rules_java_errorprone.html#donotcallgarbagecollectionexplicitly">Do not explicitly trigger a garbage collection.</a></td>
-</tr>
-<tr bgcolor="lightgrey"> 
-<td align="center">9</td>
-<td width="*%">snapbackup/src/java/org/snapbackup/utilities/ZipEngine.java</td>
-<td align="center" width="5%">145</td>
+<td align="center" width="5%">143</td>
 <td width="*"><a href="https://docs.pmd-code.org/pmd-doc-7.8.0/pmd_rules_java_errorprone.html#closeresource">Ensure that resources like this BufferedInputStream object are closed after use</a></td>
 </tr>
 </table></body></html>