openjdk: build with empty pre-version (#108994)

Some applications, like the Jetbrains IDEs, check for a suffix to
determine if a stable JDK is used.
This flag was already passed for older versions, but it got lost for
OpenJDK 14+.

pkgs/development/compilers/openjdk/14.nix

@@ -55,6 +55,7 @@ let
 
     configureFlags = [
       "--with-boot-jdk=${openjdk14-bootstrap.home}"
+      "--with-version-pre="
       "--enable-unlimited-crypto"
       "--with-native-debug-symbols=internal"
       "--with-libjpeg=system"

pkgs/development/compilers/openjdk/default.nix

@@ -55,6 +55,7 @@ let
 
     configureFlags = [
       "--with-boot-jdk=${openjdk15-bootstrap.home}"
+      "--with-version-pre="
       "--enable-unlimited-crypto"
       "--with-native-debug-symbols=internal"
       "--with-libjpeg=system"