Fix ACM fetcher import of entries (#4019)

Removed `&` sign from ID pattern

Author: Siedlerchr

CHANGELOG.md

@@ -18,6 +18,8 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 We fixed an issue where the export to clipboard functionality could not be invoked [#3994](https://github.com/JabRef/jabref/issues/3994)
 We fixed an issue with the migration of invalid Look and Feels [#3995, comment](https://github.com/JabRef/jabref/issues/3995#issuecomment-385649448)
 We fixed an issue where JabRef would no longer start, when the option "Override default font settings" was activated [#3986](https://github.com/JabRef/jabref/issues/3986)
+We fixed an issue where fetched entries from the ACM fetcher could not be imported. [#4018](https://github.com/JabRef/jabref/issues/4018)
+
 ### Removed
 We removed the GTK Look and Feel from the Options, as it leads to freezes in JabRef on MacOSX and Linux [#3995](https://github.com/JabRef/jabref/issues/3995)
 The GTK Look and Feel is now replaced with the "Nimbus" style as default.

src/main/java/org/jabref/gui/importer/fetcher/ACMPortalFetcher.java

@@ -78,7 +78,7 @@ public class ACMPortalFetcher implements PreviewEntryFetcher {
 
     private static final Pattern FULL_CITATION_PATTERN = Pattern.compile("<a href=\"(citation.cfm.*)\" target.*");
 
-    private static final Pattern ID_PATTERN = Pattern.compile("citation.cfm\\?id=(\\d+)&.*");
+    private static final Pattern ID_PATTERN = Pattern.compile("citation.cfm\\?id=(\\d+).*");
 
     // Patterns used to extract information for the preview:
     private static final Pattern TITLE_PATTERN = Pattern.compile("<a href=.*?\">([^<]*)</a>");