stop ./configure on Win32 if no library sources was specified,

the bug has been introduced in r2894

auto/lib/md5/conf

@@ -94,8 +94,10 @@ else
             CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
             MD5=YES
             MD5_LIB=$ngx_md5_lib
-        else
+        fi
+    fi
 
+    if [ $MD5 != YES ]; then
 cat << END
 
 $0: error: the HTTP cache module requires md5 functions
@@ -105,9 +107,7 @@ or build the OpenSSL library statically from the source with nginx by using
 --with-http_ssl_module --with-openssl=<path> options.
 
 END
-            exit 1
-        fi
-
+        exit 1
     fi
 
 fi

auto/lib/openssl/conf

@@ -54,7 +54,10 @@ else
             have=NGX_SSL . auto/have
             CORE_LIBS="$CORE_LIBS $ngx_feature_libs $NGX_LIBDL"
             OPENSSL=YES
-        else
+        fi
+    fi
+
+    if [ $OPENSSL != YES ]; then
 
 cat << END
 
@@ -64,8 +67,7 @@ into the system, or build the OpenSSL library statically from the source
 with nginx by using --with-openssl=<path> option.
 
 END
-            exit 1
-        fi
+        exit 1
     fi
 
 fi

auto/lib/pcre/conf

@@ -161,8 +161,10 @@ else
             CORE_INCS="$CORE_INCS $ngx_feature_path"
             CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
             PCRE=YES
-        else
+        fi
+    fi
 
+    if [ $PCRE != YES ]; then
 cat << END
 
 $0: error: the HTTP rewrite module requires the PCRE library.
@@ -171,9 +173,7 @@ option, or install the PCRE library into the system, or build the PCRE library
 statically from the source with nginx by using --with-pcre=<path> option.
 
 END
-            exit 1
-
-        fi
-
+        exit 1
     fi
+
 fi

auto/lib/zlib/conf

@@ -57,8 +57,10 @@ else
             CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
             ZLIB=YES
             ngx_found=no
-        else
+        fi
+    fi
 
+    if [ $ZLIB != YES ]; then
 cat << END
 
 $0: error: the HTTP gzip module requires the zlib library.
@@ -67,8 +69,7 @@ option, or install the zlib library into the system, or build the zlib library
 statically from the source with nginx by using --with-zlib=<path> option.
 
 END
-            exit 1
-        fi
+        exit 1
     fi
 
 fi