Cronjob ezfindexcontent fails in multicore mode because of a typo in eZSolr::commit()
=> Instead of accessing the eZSolrBase instances with "$this->SolrLanguageShards[<language>]", it uses "$this->SolrLanguageShards[<language>]->Solr", which is not defined.
=> the function eZSolr::optimize has the correct syntax.

Xdebug output below :
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Notice: Undefined property: eZSolrBase::$Solr in /var/www/myproject/www/extension/ezfind/search/plugins/ezsolr/ezsolr.php on line 590

Call Stack:
0.0321 135672 1.

{main}() /var/www/myproject/www/runcronjobs.php:0
0.2361 5174132 2. eZRunCronjobs::runScript(???, ???) /var/www/myproject/www/runcronjobs.php:356
0.2401 5279420 3. include('/var/www/myproject/www/extension/ezfind/cronjobs/ezfindexcontent.php') /var/www/myproject/www/kernel/classes/ezruncronjobs.php:76
8.3411 23279996 4. eZSolr->commit() /var/www/myproject/www/extension/ezfind/cronjobs/ezfindexcontent.php:80


Fatal error: Call to a member function commit() on a non-object in /var/www/myproject/www/extension/ezfind/search/plugins/ezsolr/ezsolr.php on line 590

Call Stack:
0.0321 135672 1. {main}

() /var/www/myproject/www/runcronjobs.php:0
0.2361 5174132 2. eZRunCronjobs::runScript(???, ???) /var/www/myproject/www/runcronjobs.php:356
0.2401 5279420 3. include('/var/www/myproject/www/extension/ezfind/cronjobs/ezfindexcontent.php') /var/www/myproject/www/kernel/classes/ezruncronjobs.php:76
8.3411 23279996 4. eZSolr->commit() /var/www/myproject/www/extension/ezfind/cronjobs/ezfindexcontent.php:80

Fatal error: eZ Publish did not finish its request
The execution of eZ Publish was abruptly ended, the debug output is present below.
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Patch included below

Steps to reproduce

a) Set up multicore environment
b) Have some objects to index with cronjob ezfindexcontent (activate DelayedIndexing for instance), then run the cronjob ezfindexcontent