fix scons weird sonames

Starting with 4.1 scons started to fill sonames on OpenBSD too but with
the major alone and not with the "major.minor"; this forces it to use
the correct format (which also makes `make port-lib-depends-check'
happy.)

prodded, tested by and ok sthen@

devel/scons/Makefile

@@ -3,6 +3,7 @@ COMMENT=	Python-based build system
 MODPY_EGG_VERSION= 4.3.0
 DISTNAME=	SCons-${MODPY_EGG_VERSION}
 PKGNAME=	${DISTNAME:L}
+REVISION=	0
 CATEGORIES=	devel
 
 HOMEPAGE=	https://www.scons.org/

devel/scons/patches/patch-SCons_Tool_linkCommon_SharedLibrary_py

@@ -0,0 +1,17 @@
+generate a soname that respects SHARED_LIBS
+
+Index: SCons/Tool/linkCommon/SharedLibrary.py
+--- SCons/Tool/linkCommon/SharedLibrary.py.orig
++++ SCons/Tool/linkCommon/SharedLibrary.py
+@@ -93,9 +93,8 @@ def _soversion(target, source, env, for_signature):
+     if "SOVERSION" in env:
+         return ".$SOVERSION"
+     elif "SHLIBVERSION" in env:
+-        shlibversion = env.subst("$SHLIBVERSION")
+-        # We use only the most significant digit of SHLIBVERSION
+-        return "." + shlibversion.split(".")[0]
++        shlibversion = env.subst("$SHLIBVERSION").split(".")
++        return "." + shlibversion[0] + "." + shlibversion[1]
+     else:
+         return ""
+