java/bouncycastle: fix compilation with jdk11 and jdk17

Some comments in source files contain UTF-8 characters.
Jdk11 and jdk17 expected ASCII and threw an error.
Tell the compiler the charset of the source files.

PR:	263601
Reported-by:	olce@
Obtained-from:	https://lists.freebsd.org/archives/freebsd-java/2025-December/003388.html

java/bouncycastle/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	bouncycastle
 DISTVERSION=	1.71
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	java security
 MASTER_SITES=	http://www.bouncycastle.org/download/ \
 		http://polydistortion.net/bc/download/

java/bouncycastle/files/patch-ant_bc+-build.xml

@@ -0,0 +1,26 @@
+--- ant/bc+-build.xml.orig	2025-12-04 21:43:00 UTC
++++ ant/bc+-build.xml
+@@ -118,6 +118,7 @@
+                 <mkdir dir="${artifacts.dir}/@{target}" />
+ 
+                 <javac source="${bc.javac.source}" target="${bc.javac.target}"
++                    encoding="UTF-8"
+                     srcdir="${artifacts.dir}/@{target}/src"
+                     destdir="${build.dir}/@{target}/classes"
+                     memoryMaximumSize="512m"
+@@ -155,6 +156,7 @@
+                 <mkdir dir="${artifacts.dir}/@{target}" />
+ 
+                 <javac source="${bc.javac.source}" target="${bc.javac.target}"
++                    encoding="UTF-8"
+                     srcdir="${artifacts.dir}/@{target}/src"
+                     destdir="${build.dir}/@{target}/classes"
+                     memoryMaximumSize="512m"
+@@ -302,6 +304,7 @@
+         </copy>
+ 
+         <javac source="${bc.javac.source}" target="${bc.javac.target}"
++            encoding="UTF-8"
+             srcdir="${lcrypto.target.src.dir}"
+             destdir="${lcrypto.target.classes.dir}"
+ 	    memoryMaximumSize="512m"